worker: avoid potential partial write of pickled data
Previously, the code wrote the pickled data using os.write(). However,
os.write() can write less bytes than passed to it. To trigger the problem, the
pickled data had to be larger than
2147479552 bytes on my system.
Instead, open a file object and pass it to pickle.dump(). This also has the
advantage that it doesn’t buffer the whole pickled data in memory.
Note that the opened file must be buffered because pickle doesn’t support
unbuffered streams because unbuffered streams’ write() method might write less
bytes than passed to it (like os.write()) but pickle.dump() relies on that all
bytes are written (see https://github.com/python/cpython/issues/93050).
The side effect of using a file object and a with statement is that wfd is
explicitly closed now while it seems like before it was implicitly closed by
process exit.
$ echo '[extensions]' >> $HGRCPATH
$ echo 'strip =' >> $HGRCPATH
$ cat >findbranch.py <<EOF
> import re
> import sys
>
> head_re = re.compile(r'^#(?:(?:\\s+([A-Za-z][A-Za-z0-9_]*)(?:\\s.*)?)|(?:\\s*))$')
>
> for line in sys.stdin:
> hmatch = head_re.match(line)
> if not hmatch:
> sys.exit(1)
> if hmatch.group(1) == 'Branch':
> sys.exit(0)
> sys.exit(1)
> EOF
$ hg init a
$ cd a
$ echo "Rev 1" >rev
$ hg add rev
$ hg commit -m "No branch."
$ hg branch abranch
marked working directory as branch abranch
(branches are permanent and global, did you want a bookmark?)
$ echo "Rev 2" >rev
$ hg commit -m "With branch."
$ hg export 0 > ../r0.patch
$ hg export 1 > ../r1.patch
$ cd ..
$ if "$PYTHON" findbranch.py < r0.patch; then
> echo "Export of default branch revision has Branch header" 1>&2
> exit 1
> fi
$ if "$PYTHON" findbranch.py < r1.patch; then
> : # Do nothing
> else
> echo "Export of branch revision is missing Branch header" 1>&2
> exit 1
> fi
Make sure import still works with branch information in patches.
$ hg init b
$ cd b
$ hg import ../r0.patch
applying ../r0.patch
$ hg import ../r1.patch
applying ../r1.patch
$ cd ..
$ hg init c
$ cd c
$ hg import --exact --no-commit ../r0.patch
applying ../r0.patch
warning: can't check exact import with --no-commit
$ hg st
A rev
$ hg revert -a
forgetting rev
$ rm rev
$ hg import --exact ../r0.patch
applying ../r0.patch
$ hg import --exact ../r1.patch
applying ../r1.patch
Test --exact and patch header separators (issue3356)
$ hg strip --no-backup .
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
>>> import re
>>> p = open('../r1.patch', 'rb').read()
>>> p = re.sub(br'Parent\s+', b'Parent ', p)
>>> open('../r1-ws.patch', 'wb').write(p) and None
$ hg import --exact ../r1-ws.patch
applying ../r1-ws.patch
$ cd ..