contrib/fuzz/fm1readmarkers_corpus.py

procutils: don't try to get `.buffer` if sys.stdin is None

While hunting down following test failure of test-chg.t on Python 3, I stumbled
the case when `.buffer` is not available as sys.stdin is None.

	--- /home/pulkit/repo/hg-committed/tests/test-chg.t
	+++ /home/pulkit/repo/hg-committed/tests/test-chg.t.err
	@@ -203,7 +203,31 @@
	   $ CHGDEBUG=1 chg version -q 0<&-
		 chg: debug: * stdio fds are missing (glob)
	     chg: debug: * execute original hg (glob)
		 -  Mercurial Distributed SCM * (glob)
		 +  Traceback (most recent call last):
		 +    File "/tmp/hgtests.avspvsq4/install/bin/hg", line 43, in <module>
		 +      dispatch.run()
		 +    File "/usr/lib/python3.6/importlib/util.py", line 233, in
		 __getattribute__
		 +      self.__spec__.loader.exec_module(self)
		 +    File "<frozen importlib._bootstrap_external>", line 678, in
		 exec_module
		 +    File "<frozen importlib._bootstrap>", line 219, in
		 _call_with_frames_removed
		 +    File
		 "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/dispatch.py", line
		 726, in <module>
		 +      class lazyaliasentry(object):
		 +    File
		 "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/dispatch.py", line
		 737, in lazyaliasentry
		 +      @util.propertycache
		 +    File "/usr/lib/python3.6/importlib/util.py", line 233, in
		 __getattribute__
		 +      self.__spec__.loader.exec_module(self)
		 +    File "<frozen importlib._bootstrap_external>", line 678, in
		 exec_module
		 +    File "<frozen importlib._bootstrap>", line 219, in
		 _call_with_frames_removed
		 +    File "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/util.py",
		 line 3473, in <module>
		 +      f=procutil.stderr,
		 +    File "/usr/lib/python3.6/importlib/util.py", line 233, in
		 __getattribute__
		 +      self.__spec__.loader.exec_module(self)
		 +    File "<frozen importlib._bootstrap_external>", line 678, in
		 exec_module
		 +    File "<frozen importlib._bootstrap>", line 219, in
		 _call_with_frames_removed
		 +    File
		 "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/utils/procutil.py",
		 line 127, in <module>
		 +      stdin = sys.stdin.buffer
		 +  AttributeError: 'NoneType' object has no attribute 'buffer'
		 +  [1]

		  server lifecycle
		   ----------------

Differential Revision: https://phab.mercurial-scm.org/D9500

from __future__ import absolute_import, print_function

import argparse
import zipfile

ap = argparse.ArgumentParser()
ap.add_argument("out", metavar="some.zip", type=str, nargs=1)
args = ap.parse_args()

with zipfile.ZipFile(args.out[0], "w", zipfile.ZIP_STORED) as zf:
    zf.writestr(
        'smallish_obsstore',
        (
            # header: fm1readmarkers should start at offset 1, and
            # read until byte 597.
            '1\x00597\x00'
            # body of obsstore file
            '\x01\x00\x00\x00vA\xd7\x02+C\x1a<)\x01,\x00\x00\x01\x03\x03\xe6'
            '\x92\xde)x\x16\xd1Xph\xc7\xa7[\xe5\xe2\x1a\xab\x1e6e\xaf\xc2\xae'
            '\xe7\xbc\x83\xe1\x88\xa5\xda\xce>O\xbd\x04\xe9\x03\xc4o\xeb\x03'
            '\x01\t\x05\x04\x1fef18operationamenduserAugie Fackler <raf@duri'
            'n42.com>\x00\x00\x00vA\xd7\x02-\x8aD\xaf-\x01,\x00\x00\x01\x03\x03'
            '\x17*\xca\x8f\x9e}i\xe0i\xbb\xdf\x9fb\x03\xd2XG?\xd3h\x98\x89\x1a'
            '=2\xeb\xc3\xc5<\xb3\x9e\xcc\x0e;#\xee\xc3\x10ux\x03\x01\t\x05\x04'
            '\x1fef18operationamenduserAugie Fackler <[e-mail]>\x00\x00'
            '\x00vA\xd7\x02Mn\xd9%\xea\x01,\x00\x00\x01\x03\x03\x98\x89\x1a='
            '2\xeb\xc3\xc5<\xb3\x9e\xcc\x0e;#\xee\xc3\x10ux\xe0*\xcaT\x86Z8J'
            '\x85)\x97\xff7\xcc)\xc1\x7f\x19\x0c\x01\x03\x01\t\x05\x04\x1fef'
            '18operationamenduserAugie Fackler <[e-mail]>\x00\x00\x00'
            'yA\xd7\x02MtA\xbfj\x01,\x00\x00\x01\x03\x03\xe0*\xcaT\x86Z8J\x85'
            ')\x97\xff7\xcc)\xc1\x7f\x19\x0c\x01\x00\x94\x01\xa9\n\xf80\x92\xa3'
            'j\xc5X\xb1\xc9:\xd51\xb8*\xa9\x03\x01\t\x08\x04\x1fef11operatio'
            'nhistedituserAugie Fackler <[e-mail]>\x00\x00\x00yA\xd7\x02'
            'MtA\xd4\xe1\x01,\x00\x00\x01\x03\x03"\xa5\xcb\x86\xb6\xf4\xbaO\xa0'
            'sH\xe7?\xcb\x9b\xc2n\xcfI\x9e\x14\xf0D\xf0!\x18DN\xcd\x97\x016\xa5'
            '\xef\xa06\xcb\x884\x8a\x03\x01\t\x08\x04\x1fef14operationhisted'
        ),
    )