lock: while releasing, unlink lockfile even if the release function throws
Consider a hypothetical bug in the release function that causes it to raise an
exception. Also consider the bisect command, which saves its state in a finally
clause. Saving the state requires acquiring the wlock.
If we don't unlink the lockfile when the exception is thrown, we'll try to
acquire the wlock again. We're going to try and acquire a lock again while our
old lockfile is on disk. The PID on disk is our own, and of course we're still
running, so we won't take over the lock. Hence we'll be stuck waiting for a
lock that we left behind ourselves.
To avoid this, always unlink the lockfile. This preserves the invariant that
self.held > 0 is equivalent to the lockfile existing on disk.
Test unionrepo functionality
Create one repository
$ hg init repo1
$ cd repo1
$ touch repo1-0
$ echo repo1-0 > f
$ hg ci -Aqmrepo1-0
$ touch repo1-1
$ echo repo1-1 >> f
$ hg ci -Aqmrepo1-1
$ touch repo1-2
$ echo repo1-2 >> f
$ hg ci -Aqmrepo1-2
$ hg log --template '{rev}:{node|short} {desc|firstline}\n'
2:68c0685446a3 repo1-2
1:8a58db72e69d repo1-1
0:f093fec0529b repo1-0
$ tip1=`hg id -q`
$ cd ..
- and a clone with a not-completely-trivial history
$ hg clone -q repo1 --rev 0 repo2
$ cd repo2
$ touch repo2-1
$ sed '1i\
> repo2-1 at top
> ' f > f.tmp
$ mv f.tmp f
$ hg ci -Aqmrepo2-1
$ touch repo2-2
$ hg pull -q ../repo1 -r 1
$ hg merge -q
$ hg ci -Aqmrepo2-2-merge
$ touch repo2-3
$ echo repo2-3 >> f
$ hg ci -mrepo2-3
$ hg log --template '{rev}:{node|short} {desc|firstline}\n'
4:2f0d178c469c repo2-3
3:9e6fb3e0b9da repo2-2-merge
2:8a58db72e69d repo1-1
1:c337dba826e7 repo2-1
0:f093fec0529b repo1-0
$ cd ..
revisions from repo2 appear as appended / pulled to repo1
$ hg -R union:repo1+repo2 log --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
4:9e6fb3e0b9da repo2-2-merge
3:c337dba826e7 repo2-1
2:68c0685446a3 repo1-2
1:8a58db72e69d repo1-1
0:f093fec0529b repo1-0
manifest can be retrieved for revisions in both repos
$ hg -R union:repo1+repo2 mani -r $tip1
f
repo1-0
repo1-1
repo1-2
$ hg -R union:repo1+repo2 mani -r 4
f
repo1-0
repo1-1
repo2-1
repo2-2
files can be retrieved form both repos
$ hg -R repo1 cat repo1/f -r2
repo1-0
repo1-1
repo1-2
$ hg -R union:repo1+repo2 cat -r$tip1 repo1/f
repo1-0
repo1-1
repo1-2
$ hg -R union:repo1+repo2 cat -r4 $TESTTMP/repo1/f
repo2-1 at top
repo1-0
repo1-1
files can be compared across repos
$ hg -R union:repo1+repo2 diff -r$tip1 -rtip
diff -r 68c0685446a3 -r 2f0d178c469c f
--- a/f Thu Jan 01 00:00:00 1970 +0000
+++ b/f Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +1,4 @@
+repo2-1 at top
repo1-0
repo1-1
-repo1-2
+repo2-3
heads from both repos are found correctly
$ hg -R union:repo1+repo2 heads --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
2:68c0685446a3 repo1-2
revsets works across repos
$ hg -R union:repo1+repo2 id -r "ancestor($tip1, 5)"
8a58db72e69d
annotate works - an indication that linkrevs works
$ hg --cwd repo1 -Runion:../repo2 annotate $TESTTMP/repo1/f -r tip
3: repo2-1 at top
0: repo1-0
1: repo1-1
5: repo2-3
union repos can be cloned ... and clones works correctly
$ hg clone -U union:repo1+repo2 repo3
requesting all changes
adding changesets
adding manifests
adding file changes
added 6 changesets with 11 changes to 6 files (+1 heads)
$ hg -R repo3 paths
default = union:repo1+repo2
$ hg -R repo3 verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
6 files, 6 changesets, 11 total revisions
$ hg -R repo3 heads --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
2:68c0685446a3 repo1-2
$ hg -R repo3 log --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
4:9e6fb3e0b9da repo2-2-merge
3:c337dba826e7 repo2-1
2:68c0685446a3 repo1-2
1:8a58db72e69d repo1-1
0:f093fec0529b repo1-0