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.
$ cat >> $HGRCPATH << EOF
> [extensions]
> absorb=
> EOF
Abort absorb if there is an unfinished operation.
$ hg init abortunresolved
$ cd abortunresolved
$ echo "foo1" > foo.whole
$ hg commit -Aqm "foo 1"
$ hg update null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo "foo2" > foo.whole
$ hg commit -Aqm "foo 2"
$ hg --config extensions.rebase= rebase -r 1 -d 0
rebasing 1:c3b6dc0e177a tip "foo 2"
merging foo.whole
warning: conflicts while merging foo.whole! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg --config extensions.rebase= absorb
abort: rebase in progress
(use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
[20]