diff tests/test-stdio.py @ 45148:a37f290a7124

windows: always work around EINVAL in case of broken pipe for stdout / stderr

In 29a905fe23ae, I missed the fact that the `winstdout` class works around two
unrelated bugs (size limit when writing to consoles and EINVAL in case of
broken pipe) and that the latter bug happens even when no console is involved.
When writing a test for this, I realized that the same problem applies to
stderr, so I applied the workaround for EINVAL to both stdout and stderr.

The size limit is worked around in the same case as before (consoles on Windows
on Python 2). For that, I changed the `winstdout` class.

--- a/tests/test-stdio.py	Fri Jul 17 00:37:33 2020 +0200
+++ b/tests/test-stdio.py	Fri Jul 17 03:28:52 2020 +0200
@@ -13,7 +13,7 @@
 import tempfile
 import unittest
 
-from mercurial import pycompat
+from mercurial import pycompat, util
 
 
 if pycompat.ispy3:
@@ -71,6 +71,34 @@
 '''
 
 
+TEST_BROKEN_PIPE_CHILD_SCRIPT = r'''
+import os
+import pickle
+
+from mercurial import dispatch
+from mercurial.utils import procutil
+
+dispatch.initstdio()
+procutil.stdin.read(1)  # wait until parent process closed pipe
+try:
+    procutil.{stream}.write(b'test')
+    procutil.{stream}.flush()
+except EnvironmentError as e:
+    with os.fdopen(
+        os.open(
+            {err_fn!r},
+            os.O_WRONLY
+            | getattr(os, 'O_BINARY', 0)
+            | getattr(os, 'O_TEMPORARY', 0),
+        ),
+        'wb',
+    ) as err_f:
+        pickle.dump(e, err_f)
+# Exit early to suppress further broken pipe errors at interpreter shutdown.
+os._exit(0)
+'''
+
+
 @contextlib.contextmanager
 def _closing(fds):
     try:
@@ -148,11 +176,15 @@
         check_output,
         python_args=[],
         post_child_check=None,
+        stdin_generator=None,
     ):
         assert stream in ('stdout', 'stderr')
-        with rwpair_generator() as (stream_receiver, child_stream), open(
-            os.devnull, 'rb'
-        ) as child_stdin:
+        if stdin_generator is None:
+            stdin_generator = open(os.devnull, 'rb')
+        with rwpair_generator() as (
+            stream_receiver,
+            child_stream,
+        ), stdin_generator as child_stdin:
             proc = subprocess.Popen(
                 [sys.executable] + python_args + ['-c', child_script],
                 stdin=child_stdin,
@@ -295,6 +327,37 @@
     def test_large_write_stderr_ptys_unbuffered(self):
         self._test_large_write('stderr', _ptys, python_args=['-u'])
 
+    def _test_broken_pipe(self, stream):
+        assert stream in ('stdout', 'stderr')
+
+        def check_output(stream_receiver, proc):
+            os.close(stream_receiver)
+            proc.stdin.write(b'x')
+            proc.stdin.close()
+
+        def post_child_check():
+            err = util.pickle.load(err_f)
+            self.assertEqual(err.errno, errno.EPIPE)
+            self.assertEqual(err.strerror, "Broken pipe")
+
+        with tempfile.NamedTemporaryFile('rb') as err_f:
+            self._test(
+                TEST_BROKEN_PIPE_CHILD_SCRIPT.format(
+                    stream=stream, err_fn=err_f.name
+                ),
+                stream,
+                _pipes,
+                check_output,
+                post_child_check=post_child_check,
+                stdin_generator=util.nullcontextmanager(subprocess.PIPE),
+            )
+
+    def test_broken_pipe_stdout(self):
+        self._test_broken_pipe('stdout')
+
+    def test_broken_pipe_stderr(self):
+        self._test_broken_pipe('stderr')
+
 
 if __name__ == '__main__':
     import silenttestrunner