rust-status: properly translate OSError to Python
This is probably never going to be called after the next few patches, but we
might as well make sure this is done correctly for the future rewrite.
Differential Revision: https://phab.mercurial-scm.org/D9319
$ cat <<EOF > merge
> import sys, os
> print("merging for", os.path.basename(sys.argv[1]))
> EOF
$ HGMERGE="$PYTHON ../merge"; export HGMERGE
$ hg init A1
$ cd A1
$ echo This is file foo1 > foo
$ echo This is file bar1 > bar
$ hg add foo bar
$ hg commit -m "commit text"
$ cd ..
$ hg clone A1 B1
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd A1
$ rm bar
$ hg remove bar
$ hg commit -m "commit test"
$ cd ../B1
$ echo This is file foo22 > foo
$ hg commit -m "commit test"
$ cd ..
$ hg clone A1 A2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone B1 B2
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd A1
$ hg pull ../B1
pulling from ../B1
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets b90e70beeb58
1 local changesets published
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m "commit test"
bar should remain deleted.
$ hg manifest --debug
f9b0e817f6a48de3564c6b2957687c5e7297c5a0 644 foo
$ cd ../B2
$ hg pull ../A2
pulling from ../A2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
new changesets e1adc944e717
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m "commit test"
bar should remain deleted.
$ hg manifest --debug
f9b0e817f6a48de3564c6b2957687c5e7297c5a0 644 foo
$ cd ..