view .hgignore @ 31063:18fb3cf572b4 stable

worker: ignore meaningless exit status indication returned by os.waitpid()

Before this patch, worker implementation assumes that os.waitpid()
with os.WNOHANG returns '(0, 0)' for still running child process. This
is explicitly specified as below in Python API document.

    os.WNOHANG
        The option for waitpid() to return immediately if no child
        process status is available immediately. The function returns
        (0, 0) in this case.

On the other hand, POSIX specification doesn't define the "stat_loc"
value returned by waitpid() with WNOHANG for such child process.

    http://pubs.opengroup.org/onlinepubs/9699919799/functions/waitpid.html

CPython implementation for os.waitpid() on POSIX doesn't take any care
of this gap, and this may cause unexpected "exit status indication"
even on POSIX conformance platform.

For example, os.waitpid() with os.WNOHANG returns non-zero "exit
status indication" on FreeBSD. This implies os.kill() with own pid or
sys.exit() with non-zero exit code, even if no child process fails.

To ignore meaningless exit status indication returned by os.waitpid(),
this patch skips subsequent steps forcibly, if os.waitpid() returns 0
as pid.

This patch also arranges examination of 'p' value for readability.

FYI, there are some issues below about this behavior reported for
CPython.

    https://bugs.python.org/issue21791
    https://bugs.python.org/issue27808

syntax: glob

*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
tests/.coverage*
tests/.testtimes*
tests/.hypothesis
tests/hypothesis-generated
tests/annotated
tests/*.err
tests/htmlcov
build
contrib/chg/chg
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
contrib/docker/ubuntu-*
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__modulepolicy__.py
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.idea/*
.asv/*
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py

# files installed with a local --pure build
mercurial/base85.py
mercurial/bdiff.py
mercurial/diffhelpers.py
mercurial/mpatch.py
mercurial/osutil.py
mercurial/parsers.py

syntax: regexp
^\.pc/
^\.(pydev)?project

# hackable windows distribution additions
^hg-python
^hg.py$