util: fix race in makedirs()
Update makedirs() to ignore EEXIST in case someone else has already created the
directory in question. Previously the ensuredirs() function existed, and was
nearly identical to makedirs() except that it fixed this race. Unfortunately
ensuredirs() was only used in 3 places, and most code uses the racy makedirs()
function. This fixes makedirs() to be non-racy, and replaces calls to
ensuredirs() with makedirs().
In particular, mercurial.scmutil.origpath() used the racy makedirs() code,
which could cause failures during "hg update" as it tried to create backup
directories.
This does slightly change the behavior of call sites using ensuredirs():
previously ensuredirs() would throw EEXIST if the path existed but was a
regular file instead of a directory. It did this by explicitly checking
os.path.isdir() after getting EEXIST. The makedirs() code did not do this and
swallowed all EEXIST errors. I kept the makedirs() behavior, since it seemed
preferable to avoid the extra stat call in the common case where this directory
already exists. If the path does happen to be a file, the caller will almost
certainly fail with an ENOTDIR error shortly afterwards anyway. I checked
the 3 existing call sites of ensuredirs(), and this seems to be the case for
them.
test that we don't interrupt the merge session if
a file-level merge failed
$ hg init repo
$ cd repo
$ echo foo > foo
$ echo a > bar
$ hg ci -Am 'add foo'
adding bar
adding foo
$ hg mv foo baz
$ echo b >> bar
$ echo quux > quux1
$ hg ci -Am 'mv foo baz'
adding quux1
$ hg up -qC 0
$ echo >> foo
$ echo c >> bar
$ echo quux > quux2
$ hg ci -Am 'change foo'
adding quux2
created new head
test with the rename on the remote side
$ HGMERGE=false hg merge
merging bar
merging foo and baz to baz
merging bar failed!
1 files updated, 1 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg resolve -l
U bar
R baz
test with the rename on the local side
$ hg up -C 1
3 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ HGMERGE=false hg merge
merging bar
merging baz and foo to baz
merging bar failed!
1 files updated, 1 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
show unresolved
$ hg resolve -l
U bar
R baz
unmark baz
$ hg resolve -u baz
show
$ hg resolve -l
U bar
U baz
$ hg st
M bar
M baz
M quux2
? bar.orig
re-resolve baz
$ hg resolve baz
merging baz and foo to baz
after resolve
$ hg resolve -l
U bar
R baz
resolve all warning
$ hg resolve
abort: no files or directories specified
(use --all to re-merge all unresolved files)
[255]
resolve all
$ hg resolve -a
merging bar
warning: conflicts while merging bar! (edit, then use 'hg resolve --mark')
[1]
after
$ hg resolve -l
U bar
R baz
$ cd ..