merge with stable
authorAugie Fackler <augie@google.com>
Fri, 24 Jan 2020 11:05:42 -0500
changeset 44237 414249be0362
parent 44236 d1c0f239193f (diff)
parent 44139 854607bf88a1 (current diff)
child 44238 161958ebf73c
merge with stable
--- a/black.toml	Fri Jan 24 11:02:59 2020 -0500
+++ b/black.toml	Fri Jan 24 11:05:42 2020 -0500
@@ -9,7 +9,6 @@
 | \.mypy_cache/
 | \.venv/
 | mercurial/thirdparty/
-| contrib/python-zstandard/
 '''
 skip-string-normalization = true
 quiet = true
--- a/contrib/examples/fix.hgrc	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/examples/fix.hgrc	Fri Jan 24 11:05:42 2020 -0500
@@ -6,7 +6,7 @@
 rustfmt:pattern = set:**.rs
 
 black:command = black --config=black.toml -
-black:pattern = set:**.py - mercurial/thirdparty/** - "contrib/python-zstandard/**"
+black:pattern = set:**.py - mercurial/thirdparty/**
 
 # Mercurial doesn't have any Go code, but if we did this is how we
 # would configure `hg fix` for Go:
--- a/contrib/packaging/inno/requirements.txt	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/packaging/inno/requirements.txt	Fri Jan 24 11:05:42 2020 -0500
@@ -8,6 +8,10 @@
     --hash=sha256:e4f3620cfea4f83eedc95b24abd9cd56f3c4b146dd0177e83a21b4eb49e21e50 \
     --hash=sha256:fd7c7c74727ddcf00e9acd26bba8da604ffec95bf1c2144e67aff7a8b50e6cef \
     # via dulwich
+configparser==4.0.2 \
+    --hash=sha256:254c1d9c79f60c45dfde850850883d5aaa7f19a23f13561243a050d5a7c3fe4c \
+    --hash=sha256:c7d282687a5308319bf3d2e7706e575c635b0a470342641c93bea0ea3b5331df \
+    # via entrypoints
 docutils==0.15.2 \
     --hash=sha256:6c4f696463b79f1fb8ba0c594b63840ebd41f059e92b31957c46b74a4599b6d0 \
     --hash=sha256:9e4d7ecfc600058e07ba661411a2b7de2fd0fafa17d1a7f7361cd47b1175c827 \
@@ -34,8 +38,7 @@
     --hash=sha256:881c4c157e45f30af185c1ffe8d549d48ac9127433f2c380c24b84572ad66297
 pywin32-ctypes==0.2.0 \
     --hash=sha256:24ffc3b341d457d48e8922352130cf2644024a4ff09762a2261fd34c36ee5942 \
-    --hash=sha256:9dc2d991b3479cc2df15930958b674a48a227d5361d413827a4cfd0b5876fc98 \
-    # via keyring
+    --hash=sha256:9dc2d991b3479cc2df15930958b674a48a227d5361d413827a4cfd0b5876fc98
 urllib3==1.25.6 \
     --hash=sha256:3de946ffbed6e6746608990594d08faac602528ac7015ac28d33cee6a45b7398 \
     --hash=sha256:9a107b99a5393caf59c7aa3c1249c16e6879447533d0887f4336dde834c7be86 \
--- a/contrib/python-zstandard/make_cffi.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/make_cffi.py	Fri Jan 24 11:05:42 2020 -0500
@@ -52,7 +52,8 @@
 
 # Headers whose preprocessed output will be fed into cdef().
 HEADERS = [
-    os.path.join(HERE, "zstd", *p) for p in (("zstd.h",), ("dictBuilder", "zdict.h"),)
+    os.path.join(HERE, "zstd", *p)
+    for p in (("zstd.h",), ("dictBuilder", "zdict.h"),)
 ]
 
 INCLUDE_DIRS = [
@@ -139,7 +140,9 @@
         env = dict(os.environ)
         if getattr(compiler, "_paths", None):
             env["PATH"] = compiler._paths
-        process = subprocess.Popen(args + [input_file], stdout=subprocess.PIPE, env=env)
+        process = subprocess.Popen(
+            args + [input_file], stdout=subprocess.PIPE, env=env
+        )
         output = process.communicate()[0]
         ret = process.poll()
         if ret:
--- a/contrib/python-zstandard/setup.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/setup.py	Fri Jan 24 11:05:42 2020 -0500
@@ -87,7 +87,9 @@
         break
 
 if not version:
-    raise Exception("could not resolve package version; " "this should never happen")
+    raise Exception(
+        "could not resolve package version; " "this should never happen"
+    )
 
 setup(
     name="zstandard",
--- a/contrib/python-zstandard/setup_zstd.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/setup_zstd.py	Fri Jan 24 11:05:42 2020 -0500
@@ -138,12 +138,16 @@
     if not system_zstd:
         sources.update([os.path.join(actual_root, p) for p in zstd_sources])
         if support_legacy:
-            sources.update([os.path.join(actual_root, p) for p in zstd_sources_legacy])
+            sources.update(
+                [os.path.join(actual_root, p) for p in zstd_sources_legacy]
+            )
     sources = list(sources)
 
     include_dirs = set([os.path.join(actual_root, d) for d in ext_includes])
     if not system_zstd:
-        include_dirs.update([os.path.join(actual_root, d) for d in zstd_includes])
+        include_dirs.update(
+            [os.path.join(actual_root, d) for d in zstd_includes]
+        )
         if support_legacy:
             include_dirs.update(
                 [os.path.join(actual_root, d) for d in zstd_includes_legacy]
--- a/contrib/python-zstandard/tests/common.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/common.py	Fri Jan 24 11:05:42 2020 -0500
@@ -50,7 +50,9 @@
         os.environ.update(old_env)
 
     if mod.backend != "cffi":
-        raise Exception("got the zstandard %s backend instead of cffi" % mod.backend)
+        raise Exception(
+            "got the zstandard %s backend instead of cffi" % mod.backend
+        )
 
     # If CFFI version is available, dynamically construct test methods
     # that use it.
@@ -84,7 +86,9 @@
                 fn.__func__.func_defaults,
                 fn.__func__.func_closure,
             )
-            new_method = types.UnboundMethodType(new_fn, fn.im_self, fn.im_class)
+            new_method = types.UnboundMethodType(
+                new_fn, fn.im_self, fn.im_class
+            )
 
         setattr(cls, name, new_method)
 
@@ -194,4 +198,6 @@
     expensive_settings = hypothesis.settings(deadline=None, max_examples=10000)
     hypothesis.settings.register_profile("expensive", expensive_settings)
 
-    hypothesis.settings.load_profile(os.environ.get("HYPOTHESIS_PROFILE", "default"))
+    hypothesis.settings.load_profile(
+        os.environ.get("HYPOTHESIS_PROFILE", "default")
+    )
--- a/contrib/python-zstandard/tests/test_buffer_util.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_buffer_util.py	Fri Jan 24 11:05:42 2020 -0500
@@ -67,7 +67,8 @@
             self.skipTest("BufferWithSegments not available")
 
         b = zstd.BufferWithSegments(
-            b"foofooxfooxy", b"".join([ss.pack(0, 3), ss.pack(3, 4), ss.pack(7, 5)])
+            b"foofooxfooxy",
+            b"".join([ss.pack(0, 3), ss.pack(3, 4), ss.pack(7, 5)]),
         )
         self.assertEqual(len(b), 3)
         self.assertEqual(b.size, 12)
@@ -83,17 +84,23 @@
         if not hasattr(zstd, "BufferWithSegmentsCollection"):
             self.skipTest("BufferWithSegmentsCollection not available")
 
-        with self.assertRaisesRegex(ValueError, "must pass at least 1 argument"):
+        with self.assertRaisesRegex(
+            ValueError, "must pass at least 1 argument"
+        ):
             zstd.BufferWithSegmentsCollection()
 
     def test_argument_validation(self):
         if not hasattr(zstd, "BufferWithSegmentsCollection"):
             self.skipTest("BufferWithSegmentsCollection not available")
 
-        with self.assertRaisesRegex(TypeError, "arguments must be BufferWithSegments"):
+        with self.assertRaisesRegex(
+            TypeError, "arguments must be BufferWithSegments"
+        ):
             zstd.BufferWithSegmentsCollection(None)
 
-        with self.assertRaisesRegex(TypeError, "arguments must be BufferWithSegments"):
+        with self.assertRaisesRegex(
+            TypeError, "arguments must be BufferWithSegments"
+        ):
             zstd.BufferWithSegmentsCollection(
                 zstd.BufferWithSegments(b"foo", ss.pack(0, 3)), None
             )
--- a/contrib/python-zstandard/tests/test_compressor.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_compressor.py	Fri Jan 24 11:05:42 2020 -0500
@@ -24,7 +24,9 @@
 
 
 def multithreaded_chunk_size(level, source_size=0):
-    params = zstd.ZstdCompressionParameters.from_level(level, source_size=source_size)
+    params = zstd.ZstdCompressionParameters.from_level(
+        level, source_size=source_size
+    )
 
     return 1 << (params.window_log + 2)
 
@@ -86,7 +88,9 @@
 
         # This matches the test for read_to_iter() below.
         cctx = zstd.ZstdCompressor(level=1, write_content_size=False)
-        result = cctx.compress(b"f" * zstd.COMPRESSION_RECOMMENDED_INPUT_SIZE + b"o")
+        result = cctx.compress(
+            b"f" * zstd.COMPRESSION_RECOMMENDED_INPUT_SIZE + b"o"
+        )
         self.assertEqual(
             result,
             b"\x28\xb5\x2f\xfd\x00\x40\x54\x00\x00"
@@ -99,7 +103,9 @@
         result = cctx.compress(b"foo" * 256)
 
     def test_no_magic(self):
-        params = zstd.ZstdCompressionParameters.from_level(1, format=zstd.FORMAT_ZSTD1)
+        params = zstd.ZstdCompressionParameters.from_level(
+            1, format=zstd.FORMAT_ZSTD1
+        )
         cctx = zstd.ZstdCompressor(compression_params=params)
         magic = cctx.compress(b"foobar")
 
@@ -223,7 +229,8 @@
 
         self.assertEqual(
             result,
-            b"\x28\xb5\x2f\xfd\x23\x8f\x55\x0f\x70\x03\x19\x00\x00" b"\x66\x6f\x6f",
+            b"\x28\xb5\x2f\xfd\x23\x8f\x55\x0f\x70\x03\x19\x00\x00"
+            b"\x66\x6f\x6f",
         )
 
     def test_multithreaded_compression_params(self):
@@ -234,7 +241,9 @@
         params = zstd.get_frame_parameters(result)
         self.assertEqual(params.content_size, 3)
 
-        self.assertEqual(result, b"\x28\xb5\x2f\xfd\x20\x03\x19\x00\x00\x66\x6f\x6f")
+        self.assertEqual(
+            result, b"\x28\xb5\x2f\xfd\x20\x03\x19\x00\x00\x66\x6f\x6f"
+        )
 
 
 @make_cffi
@@ -347,7 +356,9 @@
         )
         self.assertEqual(cobj.compress(b"bar"), b"")
         # 3 byte header plus content.
-        self.assertEqual(cobj.flush(zstd.COMPRESSOBJ_FLUSH_BLOCK), b"\x18\x00\x00bar")
+        self.assertEqual(
+            cobj.flush(zstd.COMPRESSOBJ_FLUSH_BLOCK), b"\x18\x00\x00bar"
+        )
         self.assertEqual(cobj.flush(), b"\x01\x00\x00")
 
     def test_flush_empty_block(self):
@@ -445,7 +456,9 @@
         self.assertEqual(int(r), 0)
         self.assertEqual(w, 9)
 
-        self.assertEqual(dest.getvalue(), b"\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00")
+        self.assertEqual(
+            dest.getvalue(), b"\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00"
+        )
 
     def test_large_data(self):
         source = io.BytesIO()
@@ -478,7 +491,9 @@
         cctx = zstd.ZstdCompressor(level=1, write_checksum=True)
         cctx.copy_stream(source, with_checksum)
 
-        self.assertEqual(len(with_checksum.getvalue()), len(no_checksum.getvalue()) + 4)
+        self.assertEqual(
+            len(with_checksum.getvalue()), len(no_checksum.getvalue()) + 4
+        )
 
         no_params = zstd.get_frame_parameters(no_checksum.getvalue())
         with_params = zstd.get_frame_parameters(with_checksum.getvalue())
@@ -585,7 +600,9 @@
         cctx = zstd.ZstdCompressor()
 
         with cctx.stream_reader(b"foo") as reader:
-            with self.assertRaisesRegex(ValueError, "cannot __enter__ multiple times"):
+            with self.assertRaisesRegex(
+                ValueError, "cannot __enter__ multiple times"
+            ):
                 with reader as reader2:
                     pass
 
@@ -744,7 +761,9 @@
         source = io.BytesIO(b"foobar")
 
         with cctx.stream_reader(source, size=2) as reader:
-            with self.assertRaisesRegex(zstd.ZstdError, "Src size is incorrect"):
+            with self.assertRaisesRegex(
+                zstd.ZstdError, "Src size is incorrect"
+            ):
                 reader.read(10)
 
         # Try another compression operation.
@@ -1126,7 +1145,9 @@
         self.assertFalse(no_params.has_checksum)
         self.assertTrue(with_params.has_checksum)
 
-        self.assertEqual(len(with_checksum.getvalue()), len(no_checksum.getvalue()) + 4)
+        self.assertEqual(
+            len(with_checksum.getvalue()), len(no_checksum.getvalue()) + 4
+        )
 
     def test_write_content_size(self):
         no_size = NonClosingBytesIO()
@@ -1145,7 +1166,9 @@
 
         # Declaring size will write the header.
         with_size = NonClosingBytesIO()
-        with cctx.stream_writer(with_size, size=len(b"foobar" * 256)) as compressor:
+        with cctx.stream_writer(
+            with_size, size=len(b"foobar" * 256)
+        ) as compressor:
             self.assertEqual(compressor.write(b"foobar" * 256), 0)
 
         no_params = zstd.get_frame_parameters(no_size.getvalue())
@@ -1191,7 +1214,9 @@
         self.assertFalse(no_params.has_checksum)
         self.assertFalse(with_params.has_checksum)
 
-        self.assertEqual(len(with_dict_id.getvalue()), len(no_dict_id.getvalue()) + 4)
+        self.assertEqual(
+            len(with_dict_id.getvalue()), len(no_dict_id.getvalue()) + 4
+        )
 
     def test_memory_size(self):
         cctx = zstd.ZstdCompressor(level=3)
@@ -1337,7 +1362,9 @@
         for chunk in cctx.read_to_iter(b"foobar"):
             pass
 
-        with self.assertRaisesRegex(ValueError, "must pass an object with a read"):
+        with self.assertRaisesRegex(
+            ValueError, "must pass an object with a read"
+        ):
             for chunk in cctx.read_to_iter(True):
                 pass
 
@@ -1513,7 +1540,9 @@
 
         dctx = zstd.ZstdDecompressor()
 
-        self.assertEqual(dctx.decompress(b"".join(chunks)), (b"x" * 1000) + (b"y" * 24))
+        self.assertEqual(
+            dctx.decompress(b"".join(chunks)), (b"x" * 1000) + (b"y" * 24)
+        )
 
     def test_small_chunk_size(self):
         cctx = zstd.ZstdCompressor()
@@ -1533,7 +1562,8 @@
 
         dctx = zstd.ZstdDecompressor()
         self.assertEqual(
-            dctx.decompress(b"".join(chunks), max_output_size=10000), b"foo" * 1024
+            dctx.decompress(b"".join(chunks), max_output_size=10000),
+            b"foo" * 1024,
         )
 
     def test_input_types(self):
@@ -1602,7 +1632,8 @@
         list(chunker.finish())
 
         with self.assertRaisesRegex(
-            zstd.ZstdError, r"cannot call compress\(\) after compression finished"
+            zstd.ZstdError,
+            r"cannot call compress\(\) after compression finished",
         ):
             list(chunker.compress(b"foo"))
 
@@ -1644,7 +1675,9 @@
         with self.assertRaises(TypeError):
             cctx.multi_compress_to_buffer((1, 2))
 
-        with self.assertRaisesRegex(TypeError, "item 0 not a bytes like object"):
+        with self.assertRaisesRegex(
+            TypeError, "item 0 not a bytes like object"
+        ):
             cctx.multi_compress_to_buffer([u"foo"])
 
     def test_empty_input(self):
--- a/contrib/python-zstandard/tests/test_compressor_fuzzing.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_compressor_fuzzing.py	Fri Jan 24 11:05:42 2020 -0500
@@ -28,9 +28,13 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            -1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
-    def test_stream_source_read(self, original, level, source_read_size, read_size):
+    def test_stream_source_read(
+        self, original, level, source_read_size, read_size
+    ):
         if read_size == 0:
             read_size = -1
 
@@ -58,9 +62,13 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            -1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
-    def test_buffer_source_read(self, original, level, source_read_size, read_size):
+    def test_buffer_source_read(
+        self, original, level, source_read_size, read_size
+    ):
         if read_size == 0:
             read_size = -1
 
@@ -155,9 +163,13 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
-    def test_stream_source_readinto(self, original, level, source_read_size, read_size):
+    def test_stream_source_readinto(
+        self, original, level, source_read_size, read_size
+    ):
         refctx = zstd.ZstdCompressor(level=level)
         ref_frame = refctx.compress(original)
 
@@ -184,9 +196,13 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
-    def test_buffer_source_readinto(self, original, level, source_read_size, read_size):
+    def test_buffer_source_readinto(
+        self, original, level, source_read_size, read_size
+    ):
 
         refctx = zstd.ZstdCompressor(level=level)
         ref_frame = refctx.compress(original)
@@ -285,9 +301,13 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            -1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
-    def test_stream_source_read1(self, original, level, source_read_size, read_size):
+    def test_stream_source_read1(
+        self, original, level, source_read_size, read_size
+    ):
         if read_size == 0:
             read_size = -1
 
@@ -315,9 +335,13 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            -1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
-    def test_buffer_source_read1(self, original, level, source_read_size, read_size):
+    def test_buffer_source_read1(
+        self, original, level, source_read_size, read_size
+    ):
         if read_size == 0:
             read_size = -1
 
@@ -412,7 +436,9 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
     def test_stream_source_readinto1(
         self, original, level, source_read_size, read_size
@@ -446,7 +472,9 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         source_read_size=strategies.integers(1, 16384),
-        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
+        read_size=strategies.integers(
+            1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        ),
     )
     def test_buffer_source_readinto1(
         self, original, level, source_read_size, read_size
@@ -576,7 +604,9 @@
         read_size=strategies.integers(min_value=1, max_value=1048576),
         write_size=strategies.integers(min_value=1, max_value=1048576),
     )
-    def test_read_write_size_variance(self, original, level, read_size, write_size):
+    def test_read_write_size_variance(
+        self, original, level, read_size, write_size
+    ):
         refctx = zstd.ZstdCompressor(level=level)
         ref_frame = refctx.compress(original)
 
@@ -585,7 +615,11 @@
         dest = io.BytesIO()
 
         cctx.copy_stream(
-            source, dest, size=len(original), read_size=read_size, write_size=write_size
+            source,
+            dest,
+            size=len(original),
+            read_size=read_size,
+            write_size=write_size,
         )
 
         self.assertEqual(dest.getvalue(), ref_frame)
@@ -675,7 +709,9 @@
         decompressed_chunks.append(dobj.decompress(chunk))
 
         self.assertEqual(
-            dctx.decompress(b"".join(compressed_chunks), max_output_size=len(original)),
+            dctx.decompress(
+                b"".join(compressed_chunks), max_output_size=len(original)
+            ),
             original,
         )
         self.assertEqual(b"".join(decompressed_chunks), original)
@@ -690,7 +726,9 @@
         read_size=strategies.integers(min_value=1, max_value=4096),
         write_size=strategies.integers(min_value=1, max_value=4096),
     )
-    def test_read_write_size_variance(self, original, level, read_size, write_size):
+    def test_read_write_size_variance(
+        self, original, level, read_size, write_size
+    ):
         refcctx = zstd.ZstdCompressor(level=level)
         ref_frame = refcctx.compress(original)
 
@@ -699,7 +737,10 @@
         cctx = zstd.ZstdCompressor(level=level)
         chunks = list(
             cctx.read_to_iter(
-                source, size=len(original), read_size=read_size, write_size=write_size
+                source,
+                size=len(original),
+                read_size=read_size,
+                write_size=write_size,
             )
         )
 
@@ -710,7 +751,9 @@
 class TestCompressor_multi_compress_to_buffer_fuzzing(TestCase):
     @hypothesis.given(
         original=strategies.lists(
-            strategies.sampled_from(random_input_data()), min_size=1, max_size=1024
+            strategies.sampled_from(random_input_data()),
+            min_size=1,
+            max_size=1024,
         ),
         threads=strategies.integers(min_value=1, max_value=8),
         use_dict=strategies.booleans(),
@@ -776,7 +819,8 @@
         dctx = zstd.ZstdDecompressor()
 
         self.assertEqual(
-            dctx.decompress(b"".join(chunks), max_output_size=len(original)), original
+            dctx.decompress(b"".join(chunks), max_output_size=len(original)),
+            original,
         )
 
         self.assertTrue(all(len(chunk) == chunk_size for chunk in chunks[:-1]))
@@ -794,7 +838,9 @@
         input_sizes=strategies.data(),
         flushes=strategies.data(),
     )
-    def test_flush_block(self, original, level, chunk_size, input_sizes, flushes):
+    def test_flush_block(
+        self, original, level, chunk_size, input_sizes, flushes
+    ):
         cctx = zstd.ZstdCompressor(level=level)
         chunker = cctx.chunker(chunk_size=chunk_size)
 
@@ -830,7 +876,9 @@
         decompressed_chunks.append(dobj.decompress(b"".join(chunks)))
 
         self.assertEqual(
-            dctx.decompress(b"".join(compressed_chunks), max_output_size=len(original)),
+            dctx.decompress(
+                b"".join(compressed_chunks), max_output_size=len(original)
+            ),
             original,
         )
         self.assertEqual(b"".join(decompressed_chunks), original)
--- a/contrib/python-zstandard/tests/test_data_structures.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_data_structures.py	Fri Jan 24 11:05:42 2020 -0500
@@ -65,7 +65,9 @@
         p = zstd.ZstdCompressionParameters(threads=4)
         self.assertEqual(p.threads, 4)
 
-        p = zstd.ZstdCompressionParameters(threads=2, job_size=1048576, overlap_log=6)
+        p = zstd.ZstdCompressionParameters(
+            threads=2, job_size=1048576, overlap_log=6
+        )
         self.assertEqual(p.threads, 2)
         self.assertEqual(p.job_size, 1048576)
         self.assertEqual(p.overlap_log, 6)
@@ -128,7 +130,9 @@
         with self.assertRaisesRegex(
             ValueError, "cannot specify both ldm_hash_rate_log"
         ):
-            zstd.ZstdCompressionParameters(ldm_hash_rate_log=8, ldm_hash_every_log=4)
+            zstd.ZstdCompressionParameters(
+                ldm_hash_rate_log=8, ldm_hash_every_log=4
+            )
 
         p = zstd.ZstdCompressionParameters(ldm_hash_rate_log=8)
         self.assertEqual(p.ldm_hash_every_log, 8)
@@ -137,7 +141,9 @@
         self.assertEqual(p.ldm_hash_every_log, 16)
 
     def test_overlap_log(self):
-        with self.assertRaisesRegex(ValueError, "cannot specify both overlap_log"):
+        with self.assertRaisesRegex(
+            ValueError, "cannot specify both overlap_log"
+        ):
             zstd.ZstdCompressionParameters(overlap_log=1, overlap_size_log=9)
 
         p = zstd.ZstdCompressionParameters(overlap_log=2)
@@ -169,10 +175,14 @@
                     zstd.get_frame_parameters(u"foobarbaz")
 
     def test_invalid_input_sizes(self):
-        with self.assertRaisesRegex(zstd.ZstdError, "not enough data for frame"):
+        with self.assertRaisesRegex(
+            zstd.ZstdError, "not enough data for frame"
+        ):
             zstd.get_frame_parameters(b"")
 
-        with self.assertRaisesRegex(zstd.ZstdError, "not enough data for frame"):
+        with self.assertRaisesRegex(
+            zstd.ZstdError, "not enough data for frame"
+        ):
             zstd.get_frame_parameters(zstd.FRAME_HEADER)
 
     def test_invalid_frame(self):
@@ -201,7 +211,9 @@
         self.assertTrue(params.has_checksum)
 
         # Upper 2 bits indicate content size.
-        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b"\x40\x00\xff\x00")
+        params = zstd.get_frame_parameters(
+            zstd.FRAME_HEADER + b"\x40\x00\xff\x00"
+        )
         self.assertEqual(params.content_size, 511)
         self.assertEqual(params.window_size, 1024)
         self.assertEqual(params.dict_id, 0)
@@ -215,7 +227,9 @@
         self.assertFalse(params.has_checksum)
 
         # Set multiple things.
-        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b"\x45\x40\x0f\x10\x00")
+        params = zstd.get_frame_parameters(
+            zstd.FRAME_HEADER + b"\x45\x40\x0f\x10\x00"
+        )
         self.assertEqual(params.content_size, 272)
         self.assertEqual(params.window_size, 262144)
         self.assertEqual(params.dict_id, 15)
--- a/contrib/python-zstandard/tests/test_data_structures_fuzzing.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_data_structures_fuzzing.py	Fri Jan 24 11:05:42 2020 -0500
@@ -23,7 +23,9 @@
 s_chainlog = strategies.integers(
     min_value=zstd.CHAINLOG_MIN, max_value=zstd.CHAINLOG_MAX
 )
-s_hashlog = strategies.integers(min_value=zstd.HASHLOG_MIN, max_value=zstd.HASHLOG_MAX)
+s_hashlog = strategies.integers(
+    min_value=zstd.HASHLOG_MIN, max_value=zstd.HASHLOG_MAX
+)
 s_searchlog = strategies.integers(
     min_value=zstd.SEARCHLOG_MIN, max_value=zstd.SEARCHLOG_MAX
 )
@@ -61,7 +63,14 @@
         s_strategy,
     )
     def test_valid_init(
-        self, windowlog, chainlog, hashlog, searchlog, minmatch, targetlength, strategy
+        self,
+        windowlog,
+        chainlog,
+        hashlog,
+        searchlog,
+        minmatch,
+        targetlength,
+        strategy,
     ):
         zstd.ZstdCompressionParameters(
             window_log=windowlog,
@@ -83,7 +92,14 @@
         s_strategy,
     )
     def test_estimated_compression_context_size(
-        self, windowlog, chainlog, hashlog, searchlog, minmatch, targetlength, strategy
+        self,
+        windowlog,
+        chainlog,
+        hashlog,
+        searchlog,
+        minmatch,
+        targetlength,
+        strategy,
     ):
         if minmatch == zstd.MINMATCH_MIN and strategy in (
             zstd.STRATEGY_FAST,
--- a/contrib/python-zstandard/tests/test_decompressor.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_decompressor.py	Fri Jan 24 11:05:42 2020 -0500
@@ -170,11 +170,15 @@
             dctx.decompress(compressed, max_output_size=len(source) - 1)
 
         # Input size + 1 works
-        decompressed = dctx.decompress(compressed, max_output_size=len(source) + 1)
+        decompressed = dctx.decompress(
+            compressed, max_output_size=len(source) + 1
+        )
         self.assertEqual(decompressed, source)
 
         # A much larger buffer works.
-        decompressed = dctx.decompress(compressed, max_output_size=len(source) * 64)
+        decompressed = dctx.decompress(
+            compressed, max_output_size=len(source) * 64
+        )
         self.assertEqual(decompressed, source)
 
     def test_stupidly_large_output_buffer(self):
@@ -237,7 +241,8 @@
         dctx = zstd.ZstdDecompressor(max_window_size=2 ** zstd.WINDOWLOG_MIN)
 
         with self.assertRaisesRegex(
-            zstd.ZstdError, "decompression error: Frame requires too much memory"
+            zstd.ZstdError,
+            "decompression error: Frame requires too much memory",
         ):
             dctx.decompress(frame, max_output_size=len(source))
 
@@ -291,7 +296,9 @@
         self.assertEqual(w, len(source.getvalue()))
 
     def test_read_write_size(self):
-        source = OpCountingBytesIO(zstd.ZstdCompressor().compress(b"foobarfoobar"))
+        source = OpCountingBytesIO(
+            zstd.ZstdCompressor().compress(b"foobarfoobar")
+        )
 
         dest = OpCountingBytesIO()
         dctx = zstd.ZstdDecompressor()
@@ -309,7 +316,9 @@
         dctx = zstd.ZstdDecompressor()
 
         with dctx.stream_reader(b"foo") as reader:
-            with self.assertRaisesRegex(ValueError, "cannot __enter__ multiple times"):
+            with self.assertRaisesRegex(
+                ValueError, "cannot __enter__ multiple times"
+            ):
                 with reader as reader2:
                     pass
 
@@ -474,7 +483,9 @@
         dctx = zstd.ZstdDecompressor()
 
         with dctx.stream_reader(frame) as reader:
-            with self.assertRaisesRegex(ValueError, "cannot seek to negative position"):
+            with self.assertRaisesRegex(
+                ValueError, "cannot seek to negative position"
+            ):
                 reader.seek(-1, os.SEEK_SET)
 
             reader.read(1)
@@ -490,7 +501,8 @@
                 reader.seek(-1, os.SEEK_CUR)
 
             with self.assertRaisesRegex(
-                ValueError, "zstd decompression streams cannot be seeked with SEEK_END"
+                ValueError,
+                "zstd decompression streams cannot be seeked with SEEK_END",
             ):
                 reader.seek(0, os.SEEK_END)
 
@@ -743,7 +755,9 @@
 
     def test_read_lines(self):
         cctx = zstd.ZstdCompressor()
-        source = b"\n".join(("line %d" % i).encode("ascii") for i in range(1024))
+        source = b"\n".join(
+            ("line %d" % i).encode("ascii") for i in range(1024)
+        )
 
         frame = cctx.compress(source)
 
@@ -821,7 +835,9 @@
         dobj = dctx.decompressobj()
         dobj.decompress(data)
 
-        with self.assertRaisesRegex(zstd.ZstdError, "cannot use a decompressobj"):
+        with self.assertRaisesRegex(
+            zstd.ZstdError, "cannot use a decompressobj"
+        ):
             dobj.decompress(data)
             self.assertIsNone(dobj.flush())
 
@@ -1124,7 +1140,9 @@
         # Buffer protocol works.
         dctx.read_to_iter(b"foobar")
 
-        with self.assertRaisesRegex(ValueError, "must pass an object with a read"):
+        with self.assertRaisesRegex(
+            ValueError, "must pass an object with a read"
+        ):
             b"".join(dctx.read_to_iter(True))
 
     def test_empty_input(self):
@@ -1226,7 +1244,9 @@
         decompressed = b"".join(chunks)
         self.assertEqual(decompressed, source.getvalue())
 
-    @unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
+    @unittest.skipUnless(
+        "ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set"
+    )
     def test_large_input(self):
         bytes = list(struct.Struct(">B").pack(i) for i in range(256))
         compressed = NonClosingBytesIO()
@@ -1241,13 +1261,16 @@
                     len(compressed.getvalue())
                     > zstd.DECOMPRESSION_RECOMMENDED_INPUT_SIZE
                 )
-                have_raw = input_size > zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE * 2
+                have_raw = (
+                    input_size > zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE * 2
+                )
                 if have_compressed and have_raw:
                     break
 
         compressed = io.BytesIO(compressed.getvalue())
         self.assertGreater(
-            len(compressed.getvalue()), zstd.DECOMPRESSION_RECOMMENDED_INPUT_SIZE
+            len(compressed.getvalue()),
+            zstd.DECOMPRESSION_RECOMMENDED_INPUT_SIZE,
         )
 
         dctx = zstd.ZstdDecompressor()
@@ -1303,7 +1326,9 @@
         self.assertEqual(streamed, source.getvalue())
 
     def test_read_write_size(self):
-        source = OpCountingBytesIO(zstd.ZstdCompressor().compress(b"foobarfoobar"))
+        source = OpCountingBytesIO(
+            zstd.ZstdCompressor().compress(b"foobarfoobar")
+        )
         dctx = zstd.ZstdDecompressor()
         for chunk in dctx.read_to_iter(source, read_size=1, write_size=1):
             self.assertEqual(len(chunk), 1)
@@ -1355,10 +1380,14 @@
         ):
             dctx.decompress_content_dict_chain([zstd.FRAME_HEADER])
 
-        with self.assertRaisesRegex(ValueError, "chunk 0 is not a valid zstd frame"):
+        with self.assertRaisesRegex(
+            ValueError, "chunk 0 is not a valid zstd frame"
+        ):
             dctx.decompress_content_dict_chain([b"foo" * 8])
 
-        no_size = zstd.ZstdCompressor(write_content_size=False).compress(b"foo" * 64)
+        no_size = zstd.ZstdCompressor(write_content_size=False).compress(
+            b"foo" * 64
+        )
 
         with self.assertRaisesRegex(
             ValueError, "chunk 0 missing content size in frame"
@@ -1389,10 +1418,14 @@
         ):
             dctx.decompress_content_dict_chain([initial, zstd.FRAME_HEADER])
 
-        with self.assertRaisesRegex(ValueError, "chunk 1 is not a valid zstd frame"):
+        with self.assertRaisesRegex(
+            ValueError, "chunk 1 is not a valid zstd frame"
+        ):
             dctx.decompress_content_dict_chain([initial, b"foo" * 8])
 
-        no_size = zstd.ZstdCompressor(write_content_size=False).compress(b"foo" * 64)
+        no_size = zstd.ZstdCompressor(write_content_size=False).compress(
+            b"foo" * 64
+        )
 
         with self.assertRaisesRegex(
             ValueError, "chunk 1 missing content size in frame"
@@ -1400,7 +1433,9 @@
             dctx.decompress_content_dict_chain([initial, no_size])
 
         # Corrupt second frame.
-        cctx = zstd.ZstdCompressor(dict_data=zstd.ZstdCompressionDict(b"foo" * 64))
+        cctx = zstd.ZstdCompressor(
+            dict_data=zstd.ZstdCompressionDict(b"foo" * 64)
+        )
         frame = cctx.compress(b"bar" * 64)
         frame = frame[0:12] + frame[15:]
 
@@ -1447,7 +1482,9 @@
         with self.assertRaises(TypeError):
             dctx.multi_decompress_to_buffer((1, 2))
 
-        with self.assertRaisesRegex(TypeError, "item 0 not a bytes like object"):
+        with self.assertRaisesRegex(
+            TypeError, "item 0 not a bytes like object"
+        ):
             dctx.multi_decompress_to_buffer([u"foo"])
 
         with self.assertRaisesRegex(
@@ -1491,7 +1528,9 @@
         if not hasattr(dctx, "multi_decompress_to_buffer"):
             self.skipTest("multi_decompress_to_buffer not available")
 
-        result = dctx.multi_decompress_to_buffer(frames, decompressed_sizes=sizes)
+        result = dctx.multi_decompress_to_buffer(
+            frames, decompressed_sizes=sizes
+        )
 
         self.assertEqual(len(result), len(frames))
         self.assertEqual(result.size(), sum(map(len, original)))
@@ -1582,10 +1621,15 @@
         # And a manual mode.
         b = b"".join([frames[0].tobytes(), frames[1].tobytes()])
         b1 = zstd.BufferWithSegments(
-            b, struct.pack("=QQQQ", 0, len(frames[0]), len(frames[0]), len(frames[1]))
+            b,
+            struct.pack(
+                "=QQQQ", 0, len(frames[0]), len(frames[0]), len(frames[1])
+            ),
         )
 
-        b = b"".join([frames[2].tobytes(), frames[3].tobytes(), frames[4].tobytes()])
+        b = b"".join(
+            [frames[2].tobytes(), frames[3].tobytes(), frames[4].tobytes()]
+        )
         b2 = zstd.BufferWithSegments(
             b,
             struct.pack(
--- a/contrib/python-zstandard/tests/test_decompressor_fuzzing.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_decompressor_fuzzing.py	Fri Jan 24 11:05:42 2020 -0500
@@ -196,7 +196,9 @@
         streaming=strategies.booleans(),
         source_read_size=strategies.integers(1, 1048576),
     )
-    def test_stream_source_readall(self, original, level, streaming, source_read_size):
+    def test_stream_source_readall(
+        self, original, level, streaming, source_read_size
+    ):
         cctx = zstd.ZstdCompressor(level=level)
 
         if streaming:
@@ -398,7 +400,9 @@
         write_size=strategies.integers(min_value=1, max_value=8192),
         input_sizes=strategies.data(),
     )
-    def test_write_size_variance(self, original, level, write_size, input_sizes):
+    def test_write_size_variance(
+        self, original, level, write_size, input_sizes
+    ):
         cctx = zstd.ZstdCompressor(level=level)
         frame = cctx.compress(original)
 
@@ -433,7 +437,9 @@
         read_size=strategies.integers(min_value=1, max_value=8192),
         write_size=strategies.integers(min_value=1, max_value=8192),
     )
-    def test_read_write_size_variance(self, original, level, read_size, write_size):
+    def test_read_write_size_variance(
+        self, original, level, read_size, write_size
+    ):
         cctx = zstd.ZstdCompressor(level=level)
         frame = cctx.compress(original)
 
@@ -441,7 +447,9 @@
         dest = io.BytesIO()
 
         dctx = zstd.ZstdDecompressor()
-        dctx.copy_stream(source, dest, read_size=read_size, write_size=write_size)
+        dctx.copy_stream(
+            source, dest, read_size=read_size, write_size=write_size
+        )
 
         self.assertEqual(dest.getvalue(), original)
 
@@ -490,11 +498,14 @@
         original=strategies.sampled_from(random_input_data()),
         level=strategies.integers(min_value=1, max_value=5),
         write_size=strategies.integers(
-            min_value=1, max_value=4 * zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE
+            min_value=1,
+            max_value=4 * zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE,
         ),
         chunk_sizes=strategies.data(),
     )
-    def test_random_output_sizes(self, original, level, write_size, chunk_sizes):
+    def test_random_output_sizes(
+        self, original, level, write_size, chunk_sizes
+    ):
         cctx = zstd.ZstdCompressor(level=level)
         frame = cctx.compress(original)
 
@@ -524,7 +535,9 @@
         read_size=strategies.integers(min_value=1, max_value=4096),
         write_size=strategies.integers(min_value=1, max_value=4096),
     )
-    def test_read_write_size_variance(self, original, level, read_size, write_size):
+    def test_read_write_size_variance(
+        self, original, level, read_size, write_size
+    ):
         cctx = zstd.ZstdCompressor(level=level)
         frame = cctx.compress(original)
 
@@ -532,7 +545,9 @@
 
         dctx = zstd.ZstdDecompressor()
         chunks = list(
-            dctx.read_to_iter(source, read_size=read_size, write_size=write_size)
+            dctx.read_to_iter(
+                source, read_size=read_size, write_size=write_size
+            )
         )
 
         self.assertEqual(b"".join(chunks), original)
@@ -542,7 +557,9 @@
 class TestDecompressor_multi_decompress_to_buffer_fuzzing(TestCase):
     @hypothesis.given(
         original=strategies.lists(
-            strategies.sampled_from(random_input_data()), min_size=1, max_size=1024
+            strategies.sampled_from(random_input_data()),
+            min_size=1,
+            max_size=1024,
         ),
         threads=strategies.integers(min_value=1, max_value=8),
         use_dict=strategies.booleans(),
--- a/contrib/python-zstandard/tests/test_train_dictionary.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/tests/test_train_dictionary.py	Fri Jan 24 11:05:42 2020 -0500
@@ -51,11 +51,15 @@
         self.assertEqual(d.d, 16)
 
     def test_set_dict_id(self):
-        d = zstd.train_dictionary(8192, generate_samples(), k=64, d=16, dict_id=42)
+        d = zstd.train_dictionary(
+            8192, generate_samples(), k=64, d=16, dict_id=42
+        )
         self.assertEqual(d.dict_id(), 42)
 
     def test_optimize(self):
-        d = zstd.train_dictionary(8192, generate_samples(), threads=-1, steps=1, d=16)
+        d = zstd.train_dictionary(
+            8192, generate_samples(), threads=-1, steps=1, d=16
+        )
 
         # This varies by platform.
         self.assertIn(d.k, (50, 2000))
@@ -71,10 +75,14 @@
     def test_bad_precompute_compress(self):
         d = zstd.train_dictionary(8192, generate_samples(), k=64, d=16)
 
-        with self.assertRaisesRegex(ValueError, "must specify one of level or "):
+        with self.assertRaisesRegex(
+            ValueError, "must specify one of level or "
+        ):
             d.precompute_compress()
 
-        with self.assertRaisesRegex(ValueError, "must only specify one of level or "):
+        with self.assertRaisesRegex(
+            ValueError, "must only specify one of level or "
+        ):
             d.precompute_compress(
                 level=3, compression_params=zstd.CompressionParameters()
             )
@@ -88,5 +96,7 @@
         d = zstd.ZstdCompressionDict(
             b"dictcontent" * 64, dict_type=zstd.DICT_TYPE_FULLDICT
         )
-        with self.assertRaisesRegex(zstd.ZstdError, "unable to precompute dictionary"):
+        with self.assertRaisesRegex(
+            zstd.ZstdError, "unable to precompute dictionary"
+        ):
             d.precompute_compress(level=1)
--- a/contrib/python-zstandard/zstandard/cffi.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/contrib/python-zstandard/zstandard/cffi.py	Fri Jan 24 11:05:42 2020 -0500
@@ -299,10 +299,14 @@
         _set_compression_parameter(params, lib.ZSTD_c_chainLog, chain_log)
         _set_compression_parameter(params, lib.ZSTD_c_searchLog, search_log)
         _set_compression_parameter(params, lib.ZSTD_c_minMatch, min_match)
-        _set_compression_parameter(params, lib.ZSTD_c_targetLength, target_length)
+        _set_compression_parameter(
+            params, lib.ZSTD_c_targetLength, target_length
+        )
 
         if strategy != -1 and compression_strategy != -1:
-            raise ValueError("cannot specify both compression_strategy and strategy")
+            raise ValueError(
+                "cannot specify both compression_strategy and strategy"
+            )
 
         if compression_strategy != -1:
             strategy = compression_strategy
@@ -313,12 +317,16 @@
         _set_compression_parameter(
             params, lib.ZSTD_c_contentSizeFlag, write_content_size
         )
-        _set_compression_parameter(params, lib.ZSTD_c_checksumFlag, write_checksum)
+        _set_compression_parameter(
+            params, lib.ZSTD_c_checksumFlag, write_checksum
+        )
         _set_compression_parameter(params, lib.ZSTD_c_dictIDFlag, write_dict_id)
         _set_compression_parameter(params, lib.ZSTD_c_jobSize, job_size)
 
         if overlap_log != -1 and overlap_size_log != -1:
-            raise ValueError("cannot specify both overlap_log and overlap_size_log")
+            raise ValueError(
+                "cannot specify both overlap_log and overlap_size_log"
+            )
 
         if overlap_size_log != -1:
             overlap_log = overlap_size_log
@@ -326,12 +334,16 @@
             overlap_log = 0
 
         _set_compression_parameter(params, lib.ZSTD_c_overlapLog, overlap_log)
-        _set_compression_parameter(params, lib.ZSTD_c_forceMaxWindow, force_max_window)
+        _set_compression_parameter(
+            params, lib.ZSTD_c_forceMaxWindow, force_max_window
+        )
         _set_compression_parameter(
             params, lib.ZSTD_c_enableLongDistanceMatching, enable_ldm
         )
         _set_compression_parameter(params, lib.ZSTD_c_ldmHashLog, ldm_hash_log)
-        _set_compression_parameter(params, lib.ZSTD_c_ldmMinMatch, ldm_min_match)
+        _set_compression_parameter(
+            params, lib.ZSTD_c_ldmMinMatch, ldm_min_match
+        )
         _set_compression_parameter(
             params, lib.ZSTD_c_ldmBucketSizeLog, ldm_bucket_size_log
         )
@@ -346,7 +358,9 @@
         elif ldm_hash_rate_log == -1:
             ldm_hash_rate_log = 0
 
-        _set_compression_parameter(params, lib.ZSTD_c_ldmHashRateLog, ldm_hash_rate_log)
+        _set_compression_parameter(
+            params, lib.ZSTD_c_ldmHashRateLog, ldm_hash_rate_log
+        )
 
     @property
     def format(self):
@@ -354,7 +368,9 @@
 
     @property
     def compression_level(self):
-        return _get_compression_parameter(self._params, lib.ZSTD_c_compressionLevel)
+        return _get_compression_parameter(
+            self._params, lib.ZSTD_c_compressionLevel
+        )
 
     @property
     def window_log(self):
@@ -386,7 +402,9 @@
 
     @property
     def write_content_size(self):
-        return _get_compression_parameter(self._params, lib.ZSTD_c_contentSizeFlag)
+        return _get_compression_parameter(
+            self._params, lib.ZSTD_c_contentSizeFlag
+        )
 
     @property
     def write_checksum(self):
@@ -410,7 +428,9 @@
 
     @property
     def force_max_window(self):
-        return _get_compression_parameter(self._params, lib.ZSTD_c_forceMaxWindow)
+        return _get_compression_parameter(
+            self._params, lib.ZSTD_c_forceMaxWindow
+        )
 
     @property
     def enable_ldm(self):
@@ -428,11 +448,15 @@
 
     @property
     def ldm_bucket_size_log(self):
-        return _get_compression_parameter(self._params, lib.ZSTD_c_ldmBucketSizeLog)
+        return _get_compression_parameter(
+            self._params, lib.ZSTD_c_ldmBucketSizeLog
+        )
 
     @property
     def ldm_hash_rate_log(self):
-        return _get_compression_parameter(self._params, lib.ZSTD_c_ldmHashRateLog)
+        return _get_compression_parameter(
+            self._params, lib.ZSTD_c_ldmHashRateLog
+        )
 
     @property
     def ldm_hash_every_log(self):
@@ -457,7 +481,8 @@
     zresult = lib.ZSTD_CCtxParams_setParameter(params, param, value)
     if lib.ZSTD_isError(zresult):
         raise ZstdError(
-            "unable to set compression context parameter: %s" % _zstd_error(zresult)
+            "unable to set compression context parameter: %s"
+            % _zstd_error(zresult)
         )
 
 
@@ -467,14 +492,17 @@
     zresult = lib.ZSTD_CCtxParams_getParameter(params, param, result)
     if lib.ZSTD_isError(zresult):
         raise ZstdError(
-            "unable to get compression context parameter: %s" % _zstd_error(zresult)
+            "unable to get compression context parameter: %s"
+            % _zstd_error(zresult)
         )
 
     return result[0]
 
 
 class ZstdCompressionWriter(object):
-    def __init__(self, compressor, writer, source_size, write_size, write_return_read):
+    def __init__(
+        self, compressor, writer, source_size, write_size, write_return_read
+    ):
         self._compressor = compressor
         self._writer = writer
         self._write_size = write_size
@@ -491,7 +519,9 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(compressor._cctx, source_size)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
     def __enter__(self):
         if self._closed:
@@ -595,13 +625,20 @@
 
         while in_buffer.pos < in_buffer.size:
             zresult = lib.ZSTD_compressStream2(
-                self._compressor._cctx, out_buffer, in_buffer, lib.ZSTD_e_continue
+                self._compressor._cctx,
+                out_buffer,
+                in_buffer,
+                lib.ZSTD_e_continue,
             )
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd compress error: %s" % _zstd_error(zresult)
+                )
 
             if out_buffer.pos:
-                self._writer.write(ffi.buffer(out_buffer.dst, out_buffer.pos)[:])
+                self._writer.write(
+                    ffi.buffer(out_buffer.dst, out_buffer.pos)[:]
+                )
                 total_write += out_buffer.pos
                 self._bytes_compressed += out_buffer.pos
                 out_buffer.pos = 0
@@ -637,10 +674,14 @@
                 self._compressor._cctx, out_buffer, in_buffer, flush
             )
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd compress error: %s" % _zstd_error(zresult)
+                )
 
             if out_buffer.pos:
-                self._writer.write(ffi.buffer(out_buffer.dst, out_buffer.pos)[:])
+                self._writer.write(
+                    ffi.buffer(out_buffer.dst, out_buffer.pos)[:]
+                )
                 total_write += out_buffer.pos
                 self._bytes_compressed += out_buffer.pos
                 out_buffer.pos = 0
@@ -672,7 +713,9 @@
                 self._compressor._cctx, self._out, source, lib.ZSTD_e_continue
             )
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd compress error: %s" % _zstd_error(zresult)
+                )
 
             if self._out.pos:
                 chunks.append(ffi.buffer(self._out.dst, self._out.pos)[:])
@@ -681,7 +724,10 @@
         return b"".join(chunks)
 
     def flush(self, flush_mode=COMPRESSOBJ_FLUSH_FINISH):
-        if flush_mode not in (COMPRESSOBJ_FLUSH_FINISH, COMPRESSOBJ_FLUSH_BLOCK):
+        if flush_mode not in (
+            COMPRESSOBJ_FLUSH_FINISH,
+            COMPRESSOBJ_FLUSH_BLOCK,
+        ):
             raise ValueError("flush mode not recognized")
 
         if self._finished:
@@ -768,7 +814,9 @@
                 self._in.pos = 0
 
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd compress error: %s" % _zstd_error(zresult)
+                )
 
             if self._out.pos == self._out.size:
                 yield ffi.buffer(self._out.dst, self._out.pos)[:]
@@ -780,7 +828,8 @@
 
         if self._in.src != ffi.NULL:
             raise ZstdError(
-                "cannot call flush() before consuming output from " "previous operation"
+                "cannot call flush() before consuming output from "
+                "previous operation"
             )
 
         while True:
@@ -788,7 +837,9 @@
                 self._compressor._cctx, self._out, self._in, lib.ZSTD_e_flush
             )
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd compress error: %s" % _zstd_error(zresult)
+                )
 
             if self._out.pos:
                 yield ffi.buffer(self._out.dst, self._out.pos)[:]
@@ -812,7 +863,9 @@
                 self._compressor._cctx, self._out, self._in, lib.ZSTD_e_end
             )
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd compress error: %s" % _zstd_error(zresult)
+                )
 
             if self._out.pos:
                 yield ffi.buffer(self._out.dst, self._out.pos)[:]
@@ -939,7 +992,10 @@
         old_pos = out_buffer.pos
 
         zresult = lib.ZSTD_compressStream2(
-            self._compressor._cctx, out_buffer, self._in_buffer, lib.ZSTD_e_continue
+            self._compressor._cctx,
+            out_buffer,
+            self._in_buffer,
+            lib.ZSTD_e_continue,
         )
 
         self._bytes_compressed += out_buffer.pos - old_pos
@@ -997,7 +1053,9 @@
         self._bytes_compressed += out_buffer.pos - old_pos
 
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error ending compression stream: %s", _zstd_error(zresult))
+            raise ZstdError(
+                "error ending compression stream: %s", _zstd_error(zresult)
+            )
 
         if zresult == 0:
             self._finished_output = True
@@ -1102,7 +1160,9 @@
         self._bytes_compressed += out_buffer.pos - old_pos
 
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error ending compression stream: %s", _zstd_error(zresult))
+            raise ZstdError(
+                "error ending compression stream: %s", _zstd_error(zresult)
+            )
 
         if zresult == 0:
             self._finished_output = True
@@ -1170,13 +1230,17 @@
         threads=0,
     ):
         if level > lib.ZSTD_maxCLevel():
-            raise ValueError("level must be less than %d" % lib.ZSTD_maxCLevel())
+            raise ValueError(
+                "level must be less than %d" % lib.ZSTD_maxCLevel()
+            )
 
         if threads < 0:
             threads = _cpu_count()
 
         if compression_params and write_checksum is not None:
-            raise ValueError("cannot define compression_params and " "write_checksum")
+            raise ValueError(
+                "cannot define compression_params and " "write_checksum"
+            )
 
         if compression_params and write_content_size is not None:
             raise ValueError(
@@ -1184,7 +1248,9 @@
             )
 
         if compression_params and write_dict_id is not None:
-            raise ValueError("cannot define compression_params and " "write_dict_id")
+            raise ValueError(
+                "cannot define compression_params and " "write_dict_id"
+            )
 
         if compression_params and threads:
             raise ValueError("cannot define compression_params and threads")
@@ -1201,7 +1267,9 @@
 
             self._params = ffi.gc(params, lib.ZSTD_freeCCtxParams)
 
-            _set_compression_parameter(self._params, lib.ZSTD_c_compressionLevel, level)
+            _set_compression_parameter(
+                self._params, lib.ZSTD_c_compressionLevel, level
+            )
 
             _set_compression_parameter(
                 self._params,
@@ -1210,7 +1278,9 @@
             )
 
             _set_compression_parameter(
-                self._params, lib.ZSTD_c_checksumFlag, 1 if write_checksum else 0
+                self._params,
+                lib.ZSTD_c_checksumFlag,
+                1 if write_checksum else 0,
             )
 
             _set_compression_parameter(
@@ -1218,7 +1288,9 @@
             )
 
             if threads:
-                _set_compression_parameter(self._params, lib.ZSTD_c_nbWorkers, threads)
+                _set_compression_parameter(
+                    self._params, lib.ZSTD_c_nbWorkers, threads
+                )
 
         cctx = lib.ZSTD_createCCtx()
         if cctx == ffi.NULL:
@@ -1237,10 +1309,13 @@
             )
 
     def _setup_cctx(self):
-        zresult = lib.ZSTD_CCtx_setParametersUsingCCtxParams(self._cctx, self._params)
+        zresult = lib.ZSTD_CCtx_setParametersUsingCCtxParams(
+            self._cctx, self._params
+        )
         if lib.ZSTD_isError(zresult):
             raise ZstdError(
-                "could not set compression parameters: %s" % _zstd_error(zresult)
+                "could not set compression parameters: %s"
+                % _zstd_error(zresult)
             )
 
         dict_data = self._dict_data
@@ -1259,7 +1334,8 @@
 
             if lib.ZSTD_isError(zresult):
                 raise ZstdError(
-                    "could not load compression dictionary: %s" % _zstd_error(zresult)
+                    "could not load compression dictionary: %s"
+                    % _zstd_error(zresult)
                 )
 
     def memory_size(self):
@@ -1275,7 +1351,9 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(self._cctx, len(data_buffer))
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
         out_buffer = ffi.new("ZSTD_outBuffer *")
         in_buffer = ffi.new("ZSTD_inBuffer *")
@@ -1307,11 +1385,15 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(self._cctx, size)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
         cobj = ZstdCompressionObj()
         cobj._out = ffi.new("ZSTD_outBuffer *")
-        cobj._dst_buffer = ffi.new("char[]", COMPRESSION_RECOMMENDED_OUTPUT_SIZE)
+        cobj._dst_buffer = ffi.new(
+            "char[]", COMPRESSION_RECOMMENDED_OUTPUT_SIZE
+        )
         cobj._out.dst = cobj._dst_buffer
         cobj._out.size = COMPRESSION_RECOMMENDED_OUTPUT_SIZE
         cobj._out.pos = 0
@@ -1328,7 +1410,9 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(self._cctx, size)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
         return ZstdCompressionChunker(self, chunk_size=chunk_size)
 
@@ -1353,7 +1437,9 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(self._cctx, size)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
         in_buffer = ffi.new("ZSTD_inBuffer *")
         out_buffer = ffi.new("ZSTD_outBuffer *")
@@ -1381,7 +1467,9 @@
                     self._cctx, out_buffer, in_buffer, lib.ZSTD_e_continue
                 )
                 if lib.ZSTD_isError(zresult):
-                    raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                    raise ZstdError(
+                        "zstd compress error: %s" % _zstd_error(zresult)
+                    )
 
                 if out_buffer.pos:
                     ofh.write(ffi.buffer(out_buffer.dst, out_buffer.pos))
@@ -1423,7 +1511,9 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(self._cctx, size)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
         return ZstdCompressionReader(self, source, read_size)
 
@@ -1443,7 +1533,9 @@
         if size < 0:
             size = lib.ZSTD_CONTENTSIZE_UNKNOWN
 
-        return ZstdCompressionWriter(self, writer, size, write_size, write_return_read)
+        return ZstdCompressionWriter(
+            self, writer, size, write_size, write_return_read
+        )
 
     write_to = stream_writer
 
@@ -1473,7 +1565,9 @@
 
         zresult = lib.ZSTD_CCtx_setPledgedSrcSize(self._cctx, size)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("error setting source size: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "error setting source size: %s" % _zstd_error(zresult)
+            )
 
         in_buffer = ffi.new("ZSTD_inBuffer *")
         out_buffer = ffi.new("ZSTD_outBuffer *")
@@ -1517,7 +1611,9 @@
                     self._cctx, out_buffer, in_buffer, lib.ZSTD_e_continue
                 )
                 if lib.ZSTD_isError(zresult):
-                    raise ZstdError("zstd compress error: %s" % _zstd_error(zresult))
+                    raise ZstdError(
+                        "zstd compress error: %s" % _zstd_error(zresult)
+                    )
 
                 if out_buffer.pos:
                     data = ffi.buffer(out_buffer.dst, out_buffer.pos)[:]
@@ -1596,10 +1692,14 @@
     data_buffer = ffi.from_buffer(data)
     zresult = lib.ZSTD_getFrameHeader(params, data_buffer, len(data_buffer))
     if lib.ZSTD_isError(zresult):
-        raise ZstdError("cannot get frame parameters: %s" % _zstd_error(zresult))
+        raise ZstdError(
+            "cannot get frame parameters: %s" % _zstd_error(zresult)
+        )
 
     if zresult:
-        raise ZstdError("not enough data for frame parameters; need %d bytes" % zresult)
+        raise ZstdError(
+            "not enough data for frame parameters; need %d bytes" % zresult
+        )
 
     return FrameParameters(params[0])
 
@@ -1611,9 +1711,14 @@
         self.k = k
         self.d = d
 
-        if dict_type not in (DICT_TYPE_AUTO, DICT_TYPE_RAWCONTENT, DICT_TYPE_FULLDICT):
+        if dict_type not in (
+            DICT_TYPE_AUTO,
+            DICT_TYPE_RAWCONTENT,
+            DICT_TYPE_FULLDICT,
+        ):
             raise ValueError(
-                "invalid dictionary load mode: %d; must use " "DICT_TYPE_* constants"
+                "invalid dictionary load mode: %d; must use "
+                "DICT_TYPE_* constants"
             )
 
         self._dict_type = dict_type
@@ -1630,7 +1735,9 @@
 
     def precompute_compress(self, level=0, compression_params=None):
         if level and compression_params:
-            raise ValueError("must only specify one of level or " "compression_params")
+            raise ValueError(
+                "must only specify one of level or " "compression_params"
+            )
 
         if not level and not compression_params:
             raise ValueError("must specify one of level or compression_params")
@@ -1675,7 +1782,9 @@
         if ddict == ffi.NULL:
             raise ZstdError("could not create decompression dict")
 
-        ddict = ffi.gc(ddict, lib.ZSTD_freeDDict, size=lib.ZSTD_sizeof_DDict(ddict))
+        ddict = ffi.gc(
+            ddict, lib.ZSTD_freeDDict, size=lib.ZSTD_sizeof_DDict(ddict)
+        )
         self.__dict__["_ddict"] = ddict
 
         return ddict
@@ -1805,7 +1914,9 @@
                 self._decompressor._dctx, out_buffer, in_buffer
             )
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd decompressor error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd decompressor error: %s" % _zstd_error(zresult)
+                )
 
             if zresult == 0:
                 self._finished = True
@@ -2105,16 +2216,22 @@
 
         if whence == os.SEEK_SET:
             if pos < 0:
-                raise ValueError("cannot seek to negative position with SEEK_SET")
+                raise ValueError(
+                    "cannot seek to negative position with SEEK_SET"
+                )
 
             if pos < self._bytes_decompressed:
-                raise ValueError("cannot seek zstd decompression stream " "backwards")
+                raise ValueError(
+                    "cannot seek zstd decompression stream " "backwards"
+                )
 
             read_amount = pos - self._bytes_decompressed
 
         elif whence == os.SEEK_CUR:
             if pos < 0:
-                raise ValueError("cannot seek zstd decompression stream " "backwards")
+                raise ValueError(
+                    "cannot seek zstd decompression stream " "backwards"
+                )
 
             read_amount = pos
         elif whence == os.SEEK_END:
@@ -2123,7 +2240,9 @@
             )
 
         while read_amount:
-            result = self.read(min(read_amount, DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE))
+            result = self.read(
+                min(read_amount, DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE)
+            )
 
             if not result:
                 break
@@ -2257,10 +2376,14 @@
         while in_buffer.pos < in_buffer.size:
             zresult = lib.ZSTD_decompressStream(dctx, out_buffer, in_buffer)
             if lib.ZSTD_isError(zresult):
-                raise ZstdError("zstd decompress error: %s" % _zstd_error(zresult))
+                raise ZstdError(
+                    "zstd decompress error: %s" % _zstd_error(zresult)
+                )
 
             if out_buffer.pos:
-                self._writer.write(ffi.buffer(out_buffer.dst, out_buffer.pos)[:])
+                self._writer.write(
+                    ffi.buffer(out_buffer.dst, out_buffer.pos)[:]
+                )
                 total_write += out_buffer.pos
                 out_buffer.pos = 0
 
@@ -2299,7 +2422,9 @@
 
         data_buffer = ffi.from_buffer(data)
 
-        output_size = lib.ZSTD_getFrameContentSize(data_buffer, len(data_buffer))
+        output_size = lib.ZSTD_getFrameContentSize(
+            data_buffer, len(data_buffer)
+        )
 
         if output_size == lib.ZSTD_CONTENTSIZE_ERROR:
             raise ZstdError("error determining content size from frame header")
@@ -2307,7 +2432,9 @@
             return b""
         elif output_size == lib.ZSTD_CONTENTSIZE_UNKNOWN:
             if not max_output_size:
-                raise ZstdError("could not determine content size in frame header")
+                raise ZstdError(
+                    "could not determine content size in frame header"
+                )
 
             result_buffer = ffi.new("char[]", max_output_size)
             result_size = max_output_size
@@ -2330,7 +2457,9 @@
         if lib.ZSTD_isError(zresult):
             raise ZstdError("decompression error: %s" % _zstd_error(zresult))
         elif zresult:
-            raise ZstdError("decompression error: did not decompress full frame")
+            raise ZstdError(
+                "decompression error: did not decompress full frame"
+            )
         elif output_size and out_buffer.pos != output_size:
             raise ZstdError(
                 "decompression error: decompressed %d bytes; expected %d"
@@ -2346,7 +2475,9 @@
         read_across_frames=False,
     ):
         self._ensure_dctx()
-        return ZstdDecompressionReader(self, source, read_size, read_across_frames)
+        return ZstdDecompressionReader(
+            self, source, read_size, read_across_frames
+        )
 
     def decompressobj(self, write_size=DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE):
         if write_size < 1:
@@ -2421,9 +2552,13 @@
             while in_buffer.pos < in_buffer.size:
                 assert out_buffer.pos == 0
 
-                zresult = lib.ZSTD_decompressStream(self._dctx, out_buffer, in_buffer)
+                zresult = lib.ZSTD_decompressStream(
+                    self._dctx, out_buffer, in_buffer
+                )
                 if lib.ZSTD_isError(zresult):
-                    raise ZstdError("zstd decompress error: %s" % _zstd_error(zresult))
+                    raise ZstdError(
+                        "zstd decompress error: %s" % _zstd_error(zresult)
+                    )
 
                 if out_buffer.pos:
                     data = ffi.buffer(out_buffer.dst, out_buffer.pos)[:]
@@ -2449,7 +2584,9 @@
         if not hasattr(writer, "write"):
             raise ValueError("must pass an object with a write() method")
 
-        return ZstdDecompressionWriter(self, writer, write_size, write_return_read)
+        return ZstdDecompressionWriter(
+            self, writer, write_size, write_return_read
+        )
 
     write_to = stream_writer
 
@@ -2491,7 +2628,9 @@
 
             # Flush all read data to output.
             while in_buffer.pos < in_buffer.size:
-                zresult = lib.ZSTD_decompressStream(self._dctx, out_buffer, in_buffer)
+                zresult = lib.ZSTD_decompressStream(
+                    self._dctx, out_buffer, in_buffer
+                )
                 if lib.ZSTD_isError(zresult):
                     raise ZstdError(
                         "zstd decompressor error: %s" % _zstd_error(zresult)
@@ -2521,7 +2660,9 @@
         # All chunks should be zstd frames and should have content size set.
         chunk_buffer = ffi.from_buffer(chunk)
         params = ffi.new("ZSTD_frameHeader *")
-        zresult = lib.ZSTD_getFrameHeader(params, chunk_buffer, len(chunk_buffer))
+        zresult = lib.ZSTD_getFrameHeader(
+            params, chunk_buffer, len(chunk_buffer)
+        )
         if lib.ZSTD_isError(zresult):
             raise ValueError("chunk 0 is not a valid zstd frame")
         elif zresult:
@@ -2546,7 +2687,9 @@
 
         zresult = lib.ZSTD_decompressStream(self._dctx, out_buffer, in_buffer)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("could not decompress chunk 0: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "could not decompress chunk 0: %s" % _zstd_error(zresult)
+            )
         elif zresult:
             raise ZstdError("chunk 0 did not decompress full frame")
 
@@ -2561,11 +2704,15 @@
                 raise ValueError("chunk %d must be bytes" % i)
 
             chunk_buffer = ffi.from_buffer(chunk)
-            zresult = lib.ZSTD_getFrameHeader(params, chunk_buffer, len(chunk_buffer))
+            zresult = lib.ZSTD_getFrameHeader(
+                params, chunk_buffer, len(chunk_buffer)
+            )
             if lib.ZSTD_isError(zresult):
                 raise ValueError("chunk %d is not a valid zstd frame" % i)
             elif zresult:
-                raise ValueError("chunk %d is too small to contain a zstd frame" % i)
+                raise ValueError(
+                    "chunk %d is too small to contain a zstd frame" % i
+                )
 
             if params.frameContentSize == lib.ZSTD_CONTENTSIZE_UNKNOWN:
                 raise ValueError("chunk %d missing content size in frame" % i)
@@ -2580,7 +2727,9 @@
             in_buffer.size = len(chunk_buffer)
             in_buffer.pos = 0
 
-            zresult = lib.ZSTD_decompressStream(self._dctx, out_buffer, in_buffer)
+            zresult = lib.ZSTD_decompressStream(
+                self._dctx, out_buffer, in_buffer
+            )
             if lib.ZSTD_isError(zresult):
                 raise ZstdError(
                     "could not decompress chunk %d: %s" % _zstd_error(zresult)
@@ -2597,7 +2746,9 @@
         lib.ZSTD_DCtx_reset(self._dctx, lib.ZSTD_reset_session_only)
 
         if self._max_window_size:
-            zresult = lib.ZSTD_DCtx_setMaxWindowSize(self._dctx, self._max_window_size)
+            zresult = lib.ZSTD_DCtx_setMaxWindowSize(
+                self._dctx, self._max_window_size
+            )
             if lib.ZSTD_isError(zresult):
                 raise ZstdError(
                     "unable to set max window size: %s" % _zstd_error(zresult)
@@ -2605,11 +2756,14 @@
 
         zresult = lib.ZSTD_DCtx_setFormat(self._dctx, self._format)
         if lib.ZSTD_isError(zresult):
-            raise ZstdError("unable to set decoding format: %s" % _zstd_error(zresult))
+            raise ZstdError(
+                "unable to set decoding format: %s" % _zstd_error(zresult)
+            )
 
         if self._dict_data and load_dict:
             zresult = lib.ZSTD_DCtx_refDDict(self._dctx, self._dict_data._ddict)
             if lib.ZSTD_isError(zresult):
                 raise ZstdError(
-                    "unable to reference prepared dictionary: %s" % _zstd_error(zresult)
+                    "unable to reference prepared dictionary: %s"
+                    % _zstd_error(zresult)
                 )
--- a/hgext/lfs/blobstore.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/hgext/lfs/blobstore.py	Fri Jan 24 11:05:42 2020 -0500
@@ -94,15 +94,12 @@
         pass
 
 
-class filewithprogress(object):
+class lfsuploadfile(object):
     """a file-like object that supports __len__ and read.
-
-    Useful to provide progress information for how many bytes are read.
     """
 
-    def __init__(self, fp, callback):
+    def __init__(self, fp):
         self._fp = fp
-        self._callback = callback  # func(readsize)
         fp.seek(0, os.SEEK_END)
         self._len = fp.tell()
         fp.seek(0)
@@ -113,14 +110,12 @@
     def read(self, size):
         if self._fp is None:
             return b''
-        data = self._fp.read(size)
-        if data:
-            if self._callback:
-                self._callback(len(data))
-        else:
+        return self._fp.read(size)
+
+    def close(self):
+        if self._fp is not None:
             self._fp.close()
             self._fp = None
-        return data
 
 
 class local(object):
@@ -495,15 +490,17 @@
                     _(b'detected corrupt lfs object: %s') % oid,
                     hint=_(b'run hg verify'),
                 )
-            request.data = filewithprogress(localstore.open(oid), None)
-            request.get_method = lambda: r'PUT'
-            request.add_header('Content-Type', 'application/octet-stream')
-            request.add_header('Content-Length', len(request.data))
 
         for k, v in headers:
             request.add_header(pycompat.strurl(k), pycompat.strurl(v))
 
         try:
+            if action == b'upload':
+                request.data = lfsuploadfile(localstore.open(oid))
+                request.get_method = lambda: 'PUT'
+                request.add_header('Content-Type', 'application/octet-stream')
+                request.add_header('Content-Length', len(request.data))
+
             with contextlib.closing(self.urlopener.open(request)) as res:
                 contentlength = res.info().get(b"content-length")
                 ui = self.ui  # Shorten debug lines
@@ -545,6 +542,9 @@
             raise LfsRemoteError(
                 _(b'LFS error: %s') % _urlerrorreason(ex), hint=hint
             )
+        finally:
+            if request.data:
+                request.data.close()
 
     def _batch(self, pointers, localstore, action):
         if action not in [b'upload', b'download']:
--- a/mercurial/debugcommands.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/mercurial/debugcommands.py	Fri Jan 24 11:05:42 2020 -0500
@@ -13,6 +13,7 @@
 import errno
 import operator
 import os
+import platform
 import random
 import re
 import socket
@@ -1487,6 +1488,11 @@
         pycompat.sysexecutable or _(b"unknown"),
     )
     fm.write(
+        b'pythonimplementation',
+        _(b"checking Python implementation (%s)\n"),
+        pycompat.sysbytes(platform.python_implementation()),
+    )
+    fm.write(
         b'pythonver',
         _(b"checking Python version (%s)\n"),
         (b"%d.%d.%d" % sys.version_info[:3]),
--- a/mercurial/match.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/mercurial/match.py	Fri Jan 24 11:05:42 2020 -0500
@@ -24,7 +24,7 @@
 )
 from .utils import stringutil
 
-rustmod = policy.importrust('filepatterns')
+rustmod = policy.importrust('dirstate')
 
 allpatternkinds = (
     b're',
@@ -1273,15 +1273,6 @@
     '''Convert a (normalized) pattern of any kind into a
     regular expression.
     globsuffix is appended to the regexp of globs.'''
-
-    if rustmod is not None:
-        try:
-            return rustmod.build_single_regex(kind, pat, globsuffix)
-        except rustmod.PatternError:
-            raise error.ProgrammingError(
-                b'not a regex pattern: %s:%s' % (kind, pat)
-            )
-
     if not pat and kind in (b'glob', b'relpath'):
         return b''
     if kind == b're':
@@ -1554,18 +1545,6 @@
     This is useful to debug ignore patterns.
     '''
 
-    if rustmod is not None:
-        result, warnings = rustmod.read_pattern_file(
-            filepath, bool(warn), sourceinfo,
-        )
-
-        for warning_params in warnings:
-            # Can't be easily emitted from Rust, because it would require
-            # a mechanism for both gettext and calling the `warn` function.
-            warn(_(b"%s: ignoring invalid syntax '%s'\n") % warning_params)
-
-        return result
-
     syntaxes = {
         b're': b'relre:',
         b'regexp': b'relre:',
--- a/mercurial/merge.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/mercurial/merge.py	Fri Jan 24 11:05:42 2020 -0500
@@ -2507,7 +2507,8 @@
         ### apply phase
         if not branchmerge:  # just jump to the new rev
             fp1, fp2, xp1, xp2 = fp2, nullid, xp2, b''
-        if not partial and not wc.isinmemory():
+        updatedirstate = not partial and not wc.isinmemory()
+        if updatedirstate:
             repo.hook(b'preupdate', throw=True, parent1=xp1, parent2=xp2)
             # note that we're in the middle of an update
             repo.vfs.write(b'updatestate', p2.hex())
@@ -2553,7 +2554,6 @@
                 )
             )
 
-        updatedirstate = not partial and not wc.isinmemory()
         wantfiledata = updatedirstate and not branchmerge
         stats, getfiledata = applyupdates(
             repo, actions, wc, p2, overwrite, wantfiledata, labels=labels
@@ -2574,7 +2574,7 @@
     if not branchmerge:
         sparse.prunetemporaryincludes(repo)
 
-    if not partial:
+    if updatedirstate:
         repo.hook(
             b'update', parent1=xp1, parent2=xp2, error=stats.unresolvedcount
         )
--- a/rust/Cargo.lock	Fri Jan 24 11:02:59 2020 -0500
+++ b/rust/Cargo.lock	Fri Jan 24 11:05:42 2020 -0500
@@ -124,10 +124,16 @@
 ]
 
 [[package]]
+name = "hex"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "hg-core"
 version = "0.1.0"
 dependencies = [
  "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hex 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -483,6 +489,7 @@
 "checksum either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
 "checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
 "checksum getrandom 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)" = "473a1265acc8ff1e808cd0a1af8cee3c2ee5200916058a2ca113c29f2d903571"
+"checksum hex 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "023b39be39e3a2da62a94feb433e91e8bcd37676fbc8bea371daf52b7a769a3e"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 "checksum libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)" = "74dfca3d9957906e8d1e6a0b641dc9a59848e793f1da2165889fd4f62d10d79c"
 "checksum memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88579771288728879b57485cc7d6b07d648c9f0141eb955f8ab7f9d45394468e"
--- a/rust/hg-core/Cargo.toml	Fri Jan 24 11:02:59 2020 -0500
+++ b/rust/hg-core/Cargo.toml	Fri Jan 24 11:05:42 2020 -0500
@@ -10,6 +10,7 @@
 
 [dependencies]
 byteorder = "1.3.1"
+hex = "0.4.0"
 lazy_static = "1.3.0"
 memchr = "2.2.0"
 rand = "0.6.5"
--- a/rust/hg-core/src/revlog.rs	Fri Jan 24 11:02:59 2020 -0500
+++ b/rust/hg-core/src/revlog.rs	Fri Jan 24 11:05:42 2020 -0500
@@ -5,6 +5,10 @@
 // GNU General Public License version 2 or any later version.
 //! Mercurial concepts for handling revision history
 
+pub mod node;
+pub mod nodemap;
+pub use node::{Node, NodeError};
+
 /// Mercurial revision numbers
 ///
 /// As noted in revlog.c, revision numbers are actually encoded in
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/hg-core/src/revlog/node.rs	Fri Jan 24 11:05:42 2020 -0500
@@ -0,0 +1,191 @@
+// Copyright 2019-2020 Georges Racinet <georges.racinet@octobus.net>
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+//! Definitions and utilities for Revision nodes
+//!
+//! In Mercurial code base, it is customary to call "a node" the binary SHA
+//! of a revision.
+
+use hex::{self, FromHex, FromHexError};
+
+/// The length in bytes of a `Node`
+///
+/// This constant is meant to ease refactors of this module, and
+/// are private so that calling code does not expect all nodes have
+/// the same size, should we support several formats concurrently in
+/// the future.
+const NODE_BYTES_LENGTH: usize = 20;
+
+/// The length in bytes of a `Node`
+///
+/// see also `NODES_BYTES_LENGTH` about it being private.
+const NODE_NYBBLES_LENGTH: usize = 2 * NODE_BYTES_LENGTH;
+
+/// Private alias for readability and to ease future change
+type NodeData = [u8; NODE_BYTES_LENGTH];
+
+/// Binary revision SHA
+///
+/// ## Future changes of hash size
+///
+/// To accomodate future changes of hash size, Rust callers
+/// should use the conversion methods at the boundaries (FFI, actual
+/// computation of hashes and I/O) only, and only if required.
+///
+/// All other callers outside of unit tests should just handle `Node` values
+/// and never make any assumption on the actual length, using [`nybbles_len`]
+/// if they need a loop boundary.
+///
+/// All methods that create a `Node` either take a type that enforces
+/// the size or fail immediately at runtime with [`ExactLengthRequired`].
+///
+/// [`nybbles_len`]: #method.nybbles_len
+/// [`ExactLengthRequired`]: struct.NodeError#variant.ExactLengthRequired
+#[derive(Clone, Debug, PartialEq)]
+pub struct Node {
+    data: NodeData,
+}
+
+/// The node value for NULL_REVISION
+pub const NULL_NODE: Node = Node {
+    data: [0; NODE_BYTES_LENGTH],
+};
+
+impl From<NodeData> for Node {
+    fn from(data: NodeData) -> Node {
+        Node { data }
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub enum NodeError {
+    ExactLengthRequired(usize, String),
+    HexError(FromHexError, String),
+}
+
+/// Low level utility function, also for prefixes
+fn get_nybble(s: &[u8], i: usize) -> u8 {
+    if i % 2 == 0 {
+        s[i / 2] >> 4
+    } else {
+        s[i / 2] & 0x0f
+    }
+}
+
+impl Node {
+    /// Retrieve the `i`th half-byte of the binary data.
+    ///
+    /// This is also the `i`th hexadecimal digit in numeric form,
+    /// also called a [nybble](https://en.wikipedia.org/wiki/Nibble).
+    pub fn get_nybble(&self, i: usize) -> u8 {
+        get_nybble(&self.data, i)
+    }
+
+    /// Length of the data, in nybbles
+    pub fn nybbles_len(&self) -> usize {
+        // public exposure as an instance method only, so that we can
+        // easily support several sizes of hashes if needed in the future.
+        NODE_NYBBLES_LENGTH
+    }
+
+    /// Convert from hexadecimal string representation
+    ///
+    /// Exact length is required.
+    ///
+    /// To be used in FFI and I/O only, in order to facilitate future
+    /// changes of hash format.
+    pub fn from_hex(hex: &str) -> Result<Node, NodeError> {
+        Ok(NodeData::from_hex(hex)
+            .map_err(|e| NodeError::from((e, hex)))?
+            .into())
+    }
+
+    /// Convert to hexadecimal string representation
+    ///
+    /// To be used in FFI and I/O only, in order to facilitate future
+    /// changes of hash format.
+    pub fn encode_hex(&self) -> String {
+        hex::encode(self.data)
+    }
+
+    /// Provide access to binary data
+    ///
+    /// This is needed by FFI layers, for instance to return expected
+    /// binary values to Python.
+    pub fn as_bytes(&self) -> &[u8] {
+        &self.data
+    }
+}
+
+impl From<(FromHexError, &str)> for NodeError {
+    fn from(err_offender: (FromHexError, &str)) -> Self {
+        let (err, offender) = err_offender;
+        match err {
+            FromHexError::InvalidStringLength => {
+                NodeError::ExactLengthRequired(
+                    NODE_NYBBLES_LENGTH,
+                    offender.to_string(),
+                )
+            }
+            _ => NodeError::HexError(err, offender.to_string()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn sample_node() -> Node {
+        let mut data = [0; NODE_BYTES_LENGTH];
+        data.copy_from_slice(&[
+            0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba,
+            0x98, 0x76, 0x54, 0x32, 0x10, 0xde, 0xad, 0xbe, 0xef,
+        ]);
+        data.into()
+    }
+
+    /// Pad an hexadecimal string to reach `NODE_NYBBLES_LENGTH`
+    ///
+    /// The padding is made with zeros
+    fn hex_pad_right(hex: &str) -> String {
+        let mut res = hex.to_string();
+        while res.len() < NODE_NYBBLES_LENGTH {
+            res.push('0');
+        }
+        res
+    }
+
+    fn sample_node_hex() -> String {
+        hex_pad_right("0123456789abcdeffedcba9876543210deadbeef")
+    }
+
+    #[test]
+    fn test_node_from_hex() {
+        assert_eq!(Node::from_hex(&sample_node_hex()), Ok(sample_node()));
+
+        let mut short = hex_pad_right("0123");
+        short.pop();
+        short.pop();
+        assert_eq!(
+            Node::from_hex(&short),
+            Err(NodeError::ExactLengthRequired(NODE_NYBBLES_LENGTH, short)),
+        );
+
+        let not_hex = hex_pad_right("012... oops");
+        assert_eq!(
+            Node::from_hex(&not_hex),
+            Err(NodeError::HexError(
+                FromHexError::InvalidHexCharacter { c: '.', index: 3 },
+                not_hex,
+            )),
+        );
+    }
+
+    #[test]
+    fn test_node_encode_hex() {
+        assert_eq!(sample_node().encode_hex(), sample_node_hex());
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/hg-core/src/revlog/nodemap.rs	Fri Jan 24 11:05:42 2020 -0500
@@ -0,0 +1,160 @@
+// Copyright 2018-2020 Georges Racinet <georges.racinet@octobus.net>
+//           and Mercurial contributors
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+//! Indexing facilities for fast retrieval of `Revision` from `Node`
+//!
+//! This provides a variation on the 16-ary radix tree that is
+//! provided as "nodetree" in revlog.c, ready for append-only persistence
+//! on disk.
+//!
+//! Following existing implicit conventions, the "nodemap" terminology
+//! is used in a more abstract context.
+
+use super::Revision;
+use std::fmt;
+
+/// Low level NodeTree [`Blocks`] elements
+///
+/// These are exactly as for instance on persistent storage.
+type RawElement = i32;
+
+/// High level representation of values in NodeTree
+/// [`Blocks`](struct.Block.html)
+///
+/// This is the high level representation that most algorithms should
+/// use.
+#[derive(Clone, Debug, Eq, PartialEq)]
+enum Element {
+    Rev(Revision),
+    Block(usize),
+    None,
+}
+
+impl From<RawElement> for Element {
+    /// Conversion from low level representation, after endianness conversion.
+    ///
+    /// See [`Block`](struct.Block.html) for explanation about the encoding.
+    fn from(raw: RawElement) -> Element {
+        if raw >= 0 {
+            Element::Block(raw as usize)
+        } else if raw == -1 {
+            Element::None
+        } else {
+            Element::Rev(-raw - 2)
+        }
+    }
+}
+
+impl From<Element> for RawElement {
+    fn from(element: Element) -> RawElement {
+        match element {
+            Element::None => 0,
+            Element::Block(i) => i as RawElement,
+            Element::Rev(rev) => -rev - 2,
+        }
+    }
+}
+
+/// A logical block of the `NodeTree`, packed with a fixed size.
+///
+/// These are always used in container types implementing `Index<Block>`,
+/// such as `&Block`
+///
+/// As an array of integers, its ith element encodes that the
+/// ith potential edge from the block, representing the ith hexadecimal digit
+/// (nybble) `i` is either:
+///
+/// - absent (value -1)
+/// - another `Block` in the same indexable container (value ≥ 0)
+///  - a `Revision` leaf (value ≤ -2)
+///
+/// Endianness has to be fixed for consistency on shared storage across
+/// different architectures.
+///
+/// A key difference with the C `nodetree` is that we need to be
+/// able to represent the [`Block`] at index 0, hence -1 is the empty marker
+/// rather than 0 and the `Revision` range upper limit of -2 instead of -1.
+///
+/// Another related difference is that `NULL_REVISION` (-1) is not
+/// represented at all, because we want an immutable empty nodetree
+/// to be valid.
+
+#[derive(Clone, PartialEq)]
+pub struct Block([RawElement; 16]);
+
+impl Block {
+    fn new() -> Self {
+        Block([-1; 16])
+    }
+
+    fn get(&self, nybble: u8) -> Element {
+        Element::from(RawElement::from_be(self.0[nybble as usize]))
+    }
+
+    fn set(&mut self, nybble: u8, element: Element) {
+        self.0[nybble as usize] = RawElement::to_be(element.into())
+    }
+}
+
+impl fmt::Debug for Block {
+    /// sparse representation for testing and debugging purposes
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_map()
+            .entries((0..16).filter_map(|i| match self.get(i) {
+                Element::None => None,
+                element => Some((i, element)),
+            }))
+            .finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Creates a `Block` using a syntax close to the `Debug` output
+    macro_rules! block {
+        {$($nybble:tt : $variant:ident($val:tt)),*} => (
+            {
+                let mut block = Block::new();
+                $(block.set($nybble, Element::$variant($val)));*;
+                block
+            }
+        )
+    }
+
+    #[test]
+    fn test_block_debug() {
+        let mut block = Block::new();
+        block.set(1, Element::Rev(3));
+        block.set(10, Element::Block(0));
+        assert_eq!(format!("{:?}", block), "{1: Rev(3), 10: Block(0)}");
+    }
+
+    #[test]
+    fn test_block_macro() {
+        let block = block! {5: Block(2)};
+        assert_eq!(format!("{:?}", block), "{5: Block(2)}");
+
+        let block = block! {13: Rev(15), 5: Block(2)};
+        assert_eq!(format!("{:?}", block), "{5: Block(2), 13: Rev(15)}");
+    }
+
+    #[test]
+    fn test_raw_block() {
+        let mut raw = [-1; 16];
+        raw[0] = 0;
+        raw[1] = RawElement::to_be(15);
+        raw[2] = RawElement::to_be(-2);
+        raw[3] = RawElement::to_be(-1);
+        raw[4] = RawElement::to_be(-3);
+        let block = Block(raw);
+        assert_eq!(block.get(0), Element::Block(0));
+        assert_eq!(block.get(1), Element::Block(15));
+        assert_eq!(block.get(3), Element::None);
+        assert_eq!(block.get(2), Element::Rev(0));
+        assert_eq!(block.get(4), Element::Rev(1));
+    }
+}
--- a/rust/hg-core/src/utils/hg_path.rs	Fri Jan 24 11:02:59 2020 -0500
+++ b/rust/hg-core/src/utils/hg_path.rs	Fri Jan 24 11:05:42 2020 -0500
@@ -138,6 +138,79 @@
             None
         }
     }
+
+    #[cfg(windows)]
+    /// Copied from the Python stdlib's `os.path.splitdrive` implementation.
+    ///
+    /// Split a pathname into drive/UNC sharepoint and relative path specifiers.
+    /// Returns a 2-tuple (drive_or_unc, path); either part may be empty.
+    ///
+    /// If you assign
+    ///  result = split_drive(p)
+    /// It is always true that:
+    ///  result[0] + result[1] == p
+    ///
+    /// If the path contained a drive letter, drive_or_unc will contain everything
+    /// up to and including the colon.
+    /// e.g. split_drive("c:/dir") returns ("c:", "/dir")
+    ///
+    /// If the path contained a UNC path, the drive_or_unc will contain the host
+    /// name and share up to but not including the fourth directory separator
+    /// character.
+    /// e.g. split_drive("//host/computer/dir") returns ("//host/computer", "/dir")
+    ///
+    /// Paths cannot contain both a drive letter and a UNC path.
+    pub fn split_drive<'a>(&self) -> (&HgPath, &HgPath) {
+        let bytes = self.as_bytes();
+        let is_sep = |b| std::path::is_separator(b as char);
+
+        if self.len() < 2 {
+            (HgPath::new(b""), &self)
+        } else if is_sep(bytes[0])
+            && is_sep(bytes[1])
+            && (self.len() == 2 || !is_sep(bytes[2]))
+        {
+            // Is a UNC path:
+            // vvvvvvvvvvvvvvvvvvvv drive letter or UNC path
+            // \\machine\mountpoint\directory\etc\...
+            //           directory ^^^^^^^^^^^^^^^
+
+            let machine_end_index = bytes[2..].iter().position(|b| is_sep(*b));
+            let mountpoint_start_index = if let Some(i) = machine_end_index {
+                i + 2
+            } else {
+                return (HgPath::new(b""), &self);
+            };
+
+            match bytes[mountpoint_start_index + 1..]
+                .iter()
+                .position(|b| is_sep(*b))
+            {
+                // A UNC path can't have two slashes in a row
+                // (after the initial two)
+                Some(0) => (HgPath::new(b""), &self),
+                Some(i) => {
+                    let (a, b) =
+                        bytes.split_at(mountpoint_start_index + 1 + i);
+                    (HgPath::new(a), HgPath::new(b))
+                }
+                None => (&self, HgPath::new(b"")),
+            }
+        } else if bytes[1] == b':' {
+            // Drive path c:\directory
+            let (a, b) = bytes.split_at(2);
+            (HgPath::new(a), HgPath::new(b))
+        } else {
+            (HgPath::new(b""), &self)
+        }
+    }
+
+    #[cfg(unix)]
+    /// Split a pathname into drive and path. On Posix, drive is always empty.
+    pub fn split_drive(&self) -> (&HgPath, &HgPath) {
+        (HgPath::new(b""), &self)
+    }
+
     /// Checks for errors in the path, short-circuiting at the first one.
     /// This generates fine-grained errors useful for debugging.
     /// To simply check if the path is valid during tests, use `is_valid`.
@@ -473,4 +546,101 @@
         let base = HgPath::new(b"ends/");
         assert_eq!(Some(HgPath::new(b"with/dir/")), path.relative_to(base));
     }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_split_drive() {
+        // Taken from the Python stdlib's tests
+        assert_eq!(
+            HgPath::new(br"/foo/bar").split_drive(),
+            (HgPath::new(b""), HgPath::new(br"/foo/bar"))
+        );
+        assert_eq!(
+            HgPath::new(br"foo:bar").split_drive(),
+            (HgPath::new(b""), HgPath::new(br"foo:bar"))
+        );
+        assert_eq!(
+            HgPath::new(br":foo:bar").split_drive(),
+            (HgPath::new(b""), HgPath::new(br":foo:bar"))
+        );
+        // Also try NT paths; should not split them
+        assert_eq!(
+            HgPath::new(br"c:\foo\bar").split_drive(),
+            (HgPath::new(b""), HgPath::new(br"c:\foo\bar"))
+        );
+        assert_eq!(
+            HgPath::new(b"c:/foo/bar").split_drive(),
+            (HgPath::new(b""), HgPath::new(br"c:/foo/bar"))
+        );
+        assert_eq!(
+            HgPath::new(br"\\conky\mountpoint\foo\bar").split_drive(),
+            (
+                HgPath::new(b""),
+                HgPath::new(br"\\conky\mountpoint\foo\bar")
+            )
+        );
+    }
+
+    #[test]
+    #[cfg(windows)]
+    fn test_split_drive() {
+        assert_eq!(
+            HgPath::new(br"c:\foo\bar").split_drive(),
+            (HgPath::new(br"c:"), HgPath::new(br"\foo\bar"))
+        );
+        assert_eq!(
+            HgPath::new(b"c:/foo/bar").split_drive(),
+            (HgPath::new(br"c:"), HgPath::new(br"/foo/bar"))
+        );
+        assert_eq!(
+            HgPath::new(br"\\conky\mountpoint\foo\bar").split_drive(),
+            (
+                HgPath::new(br"\\conky\mountpoint"),
+                HgPath::new(br"\foo\bar")
+            )
+        );
+        assert_eq!(
+            HgPath::new(br"//conky/mountpoint/foo/bar").split_drive(),
+            (
+                HgPath::new(br"//conky/mountpoint"),
+                HgPath::new(br"/foo/bar")
+            )
+        );
+        assert_eq!(
+            HgPath::new(br"\\\conky\mountpoint\foo\bar").split_drive(),
+            (
+                HgPath::new(br""),
+                HgPath::new(br"\\\conky\mountpoint\foo\bar")
+            )
+        );
+        assert_eq!(
+            HgPath::new(br"///conky/mountpoint/foo/bar").split_drive(),
+            (
+                HgPath::new(br""),
+                HgPath::new(br"///conky/mountpoint/foo/bar")
+            )
+        );
+        assert_eq!(
+            HgPath::new(br"\\conky\\mountpoint\foo\bar").split_drive(),
+            (
+                HgPath::new(br""),
+                HgPath::new(br"\\conky\\mountpoint\foo\bar")
+            )
+        );
+        assert_eq!(
+            HgPath::new(br"//conky//mountpoint/foo/bar").split_drive(),
+            (
+                HgPath::new(br""),
+                HgPath::new(br"//conky//mountpoint/foo/bar")
+            )
+        );
+        // UNC part containing U+0130
+        assert_eq!(
+            HgPath::new(b"//conky/MOUNTPO\xc4\xb0NT/foo/bar").split_drive(),
+            (
+                HgPath::new(b"//conky/MOUNTPO\xc4\xb0NT"),
+                HgPath::new(br"/foo/bar")
+            )
+        );
+    }
 }
--- a/rust/hg-cpython/src/exceptions.rs	Fri Jan 24 11:02:59 2020 -0500
+++ b/rust/hg-cpython/src/exceptions.rs	Fri Jan 24 11:05:42 2020 -0500
@@ -13,7 +13,7 @@
 //!
 //! [`GraphError`]: struct.GraphError.html
 use cpython::{
-    exc::{IOError, RuntimeError, ValueError},
+    exc::{RuntimeError, ValueError},
     py_exception, PyErr, Python,
 };
 use hg;
@@ -39,34 +39,6 @@
     }
 }
 
-py_exception!(rustext, PatternError, RuntimeError);
-py_exception!(rustext, PatternFileError, RuntimeError);
 py_exception!(rustext, HgPathPyError, RuntimeError);
 
-impl PatternError {
-    pub fn pynew(py: Python, inner: hg::PatternError) -> PyErr {
-        match inner {
-            hg::PatternError::UnsupportedSyntax(m) => {
-                PatternError::new(py, ("PatternError", m))
-            }
-        }
-    }
-}
-
-impl PatternFileError {
-    pub fn pynew(py: Python, inner: hg::PatternFileError) -> PyErr {
-        match inner {
-            hg::PatternFileError::IO(e) => {
-                let value = (e.raw_os_error().unwrap_or(2), e.to_string());
-                PyErr::new::<IOError, _>(py, value)
-            }
-            hg::PatternFileError::Pattern(e, l) => match e {
-                hg::PatternError::UnsupportedSyntax(m) => {
-                    PatternFileError::new(py, ("PatternFileError", m, l))
-                }
-            },
-        }
-    }
-}
-
 py_exception!(shared_ref, AlreadyBorrowed, RuntimeError);
--- a/rust/hg-cpython/src/filepatterns.rs	Fri Jan 24 11:02:59 2020 -0500
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,133 +0,0 @@
-// filepatterns.rs
-//
-// Copyright 2019, Georges Racinet <gracinet@anybox.fr>,
-// Raphaël Gomès <rgomes@octobus.net>
-//
-// This software may be used and distributed according to the terms of the
-// GNU General Public License version 2 or any later version.
-
-//! Bindings for the `hg::filepatterns` module provided by the
-//! `hg-core` crate. From Python, this will be seen as `rustext.filepatterns`
-//! and can be used as replacement for the the pure `filepatterns` Python
-//! module.
-use crate::exceptions::{PatternError, PatternFileError};
-use cpython::{
-    PyBytes, PyDict, PyModule, PyObject, PyResult, PyTuple, Python, ToPyObject,
-};
-use hg::utils::files;
-use hg::{build_single_regex, read_pattern_file, LineNumber, PatternTuple};
-use std::path::PathBuf;
-
-/// Rust does not like functions with different return signatures.
-/// The 3-tuple version is always returned by the hg-core function,
-/// the (potential) conversion is handled at this level since it is not likely
-/// to have any measurable impact on performance.
-///
-/// The Python implementation passes a function reference for `warn` instead
-/// of a boolean that is used to emit warnings while parsing. The Rust
-/// implementation chooses to accumulate the warnings and propagate them to
-/// Python upon completion. See the `readpatternfile` function in `match.py`
-/// for more details.
-fn read_pattern_file_wrapper(
-    py: Python,
-    file_path: PyObject,
-    warn: bool,
-    source_info: bool,
-) -> PyResult<PyTuple> {
-    let bytes = file_path.extract::<PyBytes>(py)?;
-    let path = files::get_path_from_bytes(bytes.data(py));
-    match read_pattern_file(path, warn) {
-        Ok((patterns, warnings)) => {
-            if source_info {
-                let itemgetter = |x: &PatternTuple| {
-                    (PyBytes::new(py, &x.0), x.1, PyBytes::new(py, &x.2))
-                };
-                let results: Vec<(PyBytes, LineNumber, PyBytes)> =
-                    patterns.iter().map(itemgetter).collect();
-                return Ok((results, warnings_to_py_bytes(py, &warnings))
-                    .to_py_object(py));
-            }
-            let itemgetter = |x: &PatternTuple| PyBytes::new(py, &x.0);
-            let results: Vec<PyBytes> =
-                patterns.iter().map(itemgetter).collect();
-            Ok(
-                (results, warnings_to_py_bytes(py, &warnings))
-                    .to_py_object(py),
-            )
-        }
-        Err(e) => Err(PatternFileError::pynew(py, e)),
-    }
-}
-
-fn warnings_to_py_bytes(
-    py: Python,
-    warnings: &[(PathBuf, Vec<u8>)],
-) -> Vec<(PyBytes, PyBytes)> {
-    warnings
-        .iter()
-        .map(|(path, syn)| {
-            (
-                PyBytes::new(py, &files::get_bytes_from_path(path)),
-                PyBytes::new(py, syn),
-            )
-        })
-        .collect()
-}
-
-fn build_single_regex_wrapper(
-    py: Python,
-    kind: PyObject,
-    pat: PyObject,
-    globsuffix: PyObject,
-) -> PyResult<PyBytes> {
-    match build_single_regex(
-        kind.extract::<PyBytes>(py)?.data(py),
-        pat.extract::<PyBytes>(py)?.data(py),
-        globsuffix.extract::<PyBytes>(py)?.data(py),
-    ) {
-        Ok(regex) => Ok(PyBytes::new(py, &regex)),
-        Err(e) => Err(PatternError::pynew(py, e)),
-    }
-}
-
-pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {
-    let dotted_name = &format!("{}.filepatterns", package);
-    let m = PyModule::new(py, dotted_name)?;
-
-    m.add(py, "__package__", package)?;
-    m.add(
-        py,
-        "__doc__",
-        "Patterns files parsing - Rust implementation",
-    )?;
-    m.add(
-        py,
-        "build_single_regex",
-        py_fn!(
-            py,
-            build_single_regex_wrapper(
-                kind: PyObject,
-                pat: PyObject,
-                globsuffix: PyObject
-            )
-        ),
-    )?;
-    m.add(
-        py,
-        "read_pattern_file",
-        py_fn!(
-            py,
-            read_pattern_file_wrapper(
-                file_path: PyObject,
-                warn: bool,
-                source_info: bool
-            )
-        ),
-    )?;
-    m.add(py, "PatternError", py.get_type::<PatternError>())?;
-    let sys = PyModule::import(py, "sys")?;
-    let sys_modules: PyDict = sys.get(py, "modules")?.extract(py)?;
-    sys_modules.set_item(py, dotted_name, &m)?;
-
-    Ok(m)
-}
--- a/rust/hg-cpython/src/lib.rs	Fri Jan 24 11:02:59 2020 -0500
+++ b/rust/hg-cpython/src/lib.rs	Fri Jan 24 11:05:42 2020 -0500
@@ -33,7 +33,6 @@
 pub mod dirstate;
 pub mod discovery;
 pub mod exceptions;
-pub mod filepatterns;
 pub mod parsers;
 pub mod revlog;
 pub mod utils;
@@ -53,25 +52,10 @@
     m.add(py, "revlog", revlog::init_module(py, &dotted_name)?)?;
     m.add(
         py,
-        "filepatterns",
-        filepatterns::init_module(py, &dotted_name)?,
-    )?;
-    m.add(
-        py,
         "parsers",
         parsers::init_parsers_module(py, &dotted_name)?,
     )?;
     m.add(py, "GraphError", py.get_type::<exceptions::GraphError>())?;
-    m.add(
-        py,
-        "PatternFileError",
-        py.get_type::<exceptions::PatternFileError>(),
-    )?;
-    m.add(
-        py,
-        "PatternError",
-        py.get_type::<exceptions::PatternError>(),
-    )?;
     Ok(())
 });
 
--- a/tests/run-tests.py	Fri Jan 24 11:02:59 2020 -0500
+++ b/tests/run-tests.py	Fri Jan 24 11:05:42 2020 -0500
@@ -555,12 +555,6 @@
         help="use pure Python code instead of C extensions",
     )
     hgconf.add_argument(
-        "-3",
-        "--py3-warnings",
-        action="store_true",
-        help="enable Py3k warnings on Python 2.7+",
-    )
-    hgconf.add_argument(
         "--with-chg",
         metavar="CHG",
         help="use specified chg wrapper in place of hg",
@@ -748,9 +742,6 @@
             )
         options.timeout = 0
         options.slowtimeout = 0
-    if options.py3_warnings:
-        if PYTHON3:
-            parser.error('--py3-warnings can only be used on Python 2.7')
 
     if options.blacklist:
         options.blacklist = parselistfiles(options.blacklist, 'blacklist')
@@ -909,7 +900,6 @@
         timeout=None,
         startport=None,
         extraconfigopts=None,
-        py3warnings=False,
         shell=None,
         hgcommand=None,
         slowtimeout=None,
@@ -942,8 +932,6 @@
         must have the form "key=value" (something understood by hgrc). Values
         of the form "foo.key=value" will result in "[foo] key=value".
 
-        py3warnings enables Py3k warnings.
-
         shell is the shell to execute tests in.
         """
         if timeout is None:
@@ -968,7 +956,6 @@
         self._slowtimeout = slowtimeout
         self._startport = startport
         self._extraconfigopts = extraconfigopts or []
-        self._py3warnings = py3warnings
         self._shell = _bytespath(shell)
         self._hgcommand = hgcommand or b'hg'
         self._usechg = usechg
@@ -1515,9 +1502,8 @@
         return os.path.join(self._testdir, b'%s.out' % self.bname)
 
     def _run(self, env):
-        py3switch = self._py3warnings and b' -3' or b''
         # Quote the python(3) executable for Windows
-        cmd = b'"%s"%s "%s"' % (PYTHON, py3switch, self.path)
+        cmd = b'"%s" "%s"' % (PYTHON, self.path)
         vlog("# Running", cmd.decode("utf-8"))
         normalizenewlines = os.name == 'nt'
         result = self._runcommand(cmd, env, normalizenewlines=normalizenewlines)
@@ -3366,7 +3352,6 @@
             timeout=self.options.timeout,
             startport=self._getport(count),
             extraconfigopts=self.options.extra_config_opt,
-            py3warnings=self.options.py3_warnings,
             shell=self.options.shell,
             hgcommand=self._hgcommand,
             usechg=bool(self.options.with_chg or self.options.chg),
@@ -3512,15 +3497,6 @@
 
         self._usecorrectpython()
 
-        if self.options.py3_warnings and not self.options.anycoverage:
-            vlog("# Updating hg command to enable Py3k Warnings switch")
-            with open(os.path.join(self._bindir, 'hg'), 'rb') as f:
-                lines = [line.rstrip() for line in f]
-                lines[0] += ' -3'
-            with open(os.path.join(self._bindir, 'hg'), 'wb') as f:
-                for line in lines:
-                    f.write(line + '\n')
-
         hgbat = os.path.join(self._bindir, b'hg.bat')
         if os.path.isfile(hgbat):
             # hg.bat expects to be put in bin/scripts while run-tests.py
--- a/tests/test-check-format.t	Fri Jan 24 11:02:59 2020 -0500
+++ b/tests/test-check-format.t	Fri Jan 24 11:05:42 2020 -0500
@@ -1,5 +1,5 @@
 #require black
 
   $ cd $RUNTESTDIR/..
-  $ black --config=black.toml --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/** - "contrib/python-zstandard/**"'`
+  $ black --config=black.toml --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/**'`
 
--- a/tests/test-install.t	Fri Jan 24 11:02:59 2020 -0500
+++ b/tests/test-install.t	Fri Jan 24 11:05:42 2020 -0500
@@ -2,6 +2,7 @@
   $ hg debuginstall
   checking encoding (ascii)...
   checking Python executable (*) (glob)
+  checking Python implementation (*) (glob)
   checking Python version (2.*) (glob) (no-py3 !)
   checking Python version (3.*) (glob) (py3 !)
   checking Python lib (.*[Ll]ib.*)... (re)
@@ -43,6 +44,7 @@
     "hgverextra": "*", (glob)
     "problems": 0,
     "pythonexe": "*", (glob)
+    "pythonimplementation": "*", (glob)
     "pythonlib": "*", (glob)
     "pythonsecurity": [*], (glob)
     "pythonver": "*.*.*", (glob)
@@ -58,6 +60,7 @@
   $ HGUSER= hg debuginstall
   checking encoding (ascii)...
   checking Python executable (*) (glob)
+  checking Python implementation (*) (glob)
   checking Python version (2.*) (glob) (no-py3 !)
   checking Python version (3.*) (glob) (py3 !)
   checking Python lib (.*[Ll]ib.*)... (re)
@@ -103,6 +106,7 @@
   $ HGEDITOR="~/tools/testeditor.exe" hg debuginstall
   checking encoding (ascii)...
   checking Python executable (*) (glob)
+  checking Python implementation (*) (glob)
   checking Python version (2.*) (glob) (no-py3 !)
   checking Python version (3.*) (glob) (py3 !)
   checking Python lib (.*[Ll]ib.*)... (re)
@@ -128,6 +132,7 @@
   $ HGEDITOR="c:\foo\bar\baz.exe -y -z" hg debuginstall
   checking encoding (ascii)...
   checking Python executable (*) (glob)
+  checking Python implementation (*) (glob)
   checking Python version (2.*) (glob) (no-py3 !)
   checking Python version (3.*) (glob) (py3 !)
   checking Python lib (.*[Ll]ib.*)... (re)
@@ -185,6 +190,7 @@
   $ ./installenv/*/hg debuginstall || cat pip.log
   checking encoding (ascii)...
   checking Python executable (*) (glob)
+  checking Python implementation (*) (glob)
   checking Python version (3.*) (glob)
   checking Python lib (*)... (glob)
   checking Python security support (*) (glob)
@@ -221,6 +227,7 @@
   $ ./installenv/*/hg debuginstall || cat pip.log
   checking encoding (ascii)...
   checking Python executable (*) (glob)
+  checking Python implementation (*) (glob)
   checking Python version (2.*) (glob)
   checking Python lib (*)... (glob)
   checking Python security support (*) (glob)
--- a/tests/test-rebase-collapse.t	Fri Jan 24 11:02:59 2020 -0500
+++ b/tests/test-rebase-collapse.t	Fri Jan 24 11:05:42 2020 -0500
@@ -486,61 +486,6 @@
   abort: cannot collapse multiple named branches
   [255]
 
-  $ repeatchange() {
-  >   hg checkout $1
-  >   hg cp d z
-  >   echo blah >> z
-  >   hg commit -Am "$2" --user "$3"
-  > }
-  $ repeatchange 3 "E" "user1"
-  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
-  $ repeatchange 3 "E" "user2"
-  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
-  created new head
-  $ hg tglog
-  @  5: fbfb97b1089a 'E'
-  |
-  | o  4: f338eb3c2c7c 'E'
-  |/
-  o  3: 41acb9dca9eb 'D'
-  |
-  | o  2: 8ac4a08debf1 'C' two
-  | |
-  | o  1: 1ba175478953 'B' one
-  |/
-  o  0: 1994f17a630e 'A'
-  
-  $ hg rebase -s 5 -d 4
-  rebasing 5:fbfb97b1089a "E" (tip)
-  note: not rebasing 5:fbfb97b1089a "E" (tip), its destination already has all its changes
-  saved backup bundle to $TESTTMP/e/.hg/strip-backup/fbfb97b1089a-553e1d85-rebase.hg
-  $ hg tglog
-  @  4: f338eb3c2c7c 'E'
-  |
-  o  3: 41acb9dca9eb 'D'
-  |
-  | o  2: 8ac4a08debf1 'C' two
-  | |
-  | o  1: 1ba175478953 'B' one
-  |/
-  o  0: 1994f17a630e 'A'
-  
-  $ hg export tip
-  # HG changeset patch
-  # User user1
-  # Date 0 0
-  #      Thu Jan 01 00:00:00 1970 +0000
-  # Node ID f338eb3c2c7cc5b5915676a2376ba7ac558c5213
-  # Parent  41acb9dca9eb976e84cd21fcb756b4afa5a35c09
-  E
-  
-  diff -r 41acb9dca9eb -r f338eb3c2c7c z
-  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
-  +++ b/z	Thu Jan 01 00:00:00 1970 +0000
-  @@ -0,0 +1,2 @@
-  +d
-  +blah
-
   $ cd ..
 
 Rebase, collapse and copies
--- a/tests/test-rebase-rename.t	Fri Jan 24 11:02:59 2020 -0500
+++ b/tests/test-rebase-rename.t	Fri Jan 24 11:05:42 2020 -0500
@@ -108,6 +108,62 @@
   
   
 
+  $ repeatchange() {
+  >   hg checkout $1
+  >   hg cp a z
+  >   echo blah >> z
+  >   hg commit -Am "$2" --user "$3"
+  > }
+  $ repeatchange 1 "E" "user1"
+  2 files updated, 0 files merged, 3 files removed, 0 files unresolved
+  created new head
+  $ repeatchange 1 "E" "user2"
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  created new head
+  $ hg tglog
+  @  5: af8ad1f97097 'E'
+  |
+  | o  4: 60f545c27784 'E'
+  |/
+  | o  3: 032a9b75e83b 'rename A'
+  | |
+  | o  2: 220d0626d185 'rename B'
+  |/
+  o  1: 3ab5da9a5c01 'B'
+  |
+  o  0: 1994f17a630e 'A'
+  
+  $ hg rebase -s 5 -d 4
+  rebasing 5:af8ad1f97097 "E" (tip)
+  note: not rebasing 5:af8ad1f97097 "E" (tip), its destination already has all its changes
+  saved backup bundle to $TESTTMP/a/.hg/strip-backup/af8ad1f97097-c3e90708-rebase.hg
+  $ hg tglog
+  @  4: 60f545c27784 'E'
+  |
+  | o  3: 032a9b75e83b 'rename A'
+  | |
+  | o  2: 220d0626d185 'rename B'
+  |/
+  o  1: 3ab5da9a5c01 'B'
+  |
+  o  0: 1994f17a630e 'A'
+  
+  $ hg export tip
+  # HG changeset patch
+  # User user1
+  # Date 0 0
+  #      Thu Jan 01 00:00:00 1970 +0000
+  # Node ID 60f545c277846e6bad309919bae3ae106f59cb39
+  # Parent  3ab5da9a5c01faa02c20f2ec4870a4f689c92da6
+  E
+  
+  diff -r 3ab5da9a5c01 -r 60f545c27784 z
+  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/z	Thu Jan 01 00:00:00 1970 +0000
+  @@ -0,0 +1,2 @@
+  +a
+  +blah
+
   $ cd ..