changectx: increase perf of walk function
When running 'hg cat -r . <file>' it was doing an expensive ctx.walk(m) which
applied the regex to every file in the manifest.
This changes changectx.walk to iterate over just the files in the regex, if no
other patterns are specified. This cuts hg cat time by 50% in our repo and
probably benefits a few other commands as well.
test that a commit clears the merge state.
$ hg init repo
$ cd repo
$ echo foo > file
$ hg commit -Am 'add file'
adding file
$ echo bar >> file
$ hg commit -Am 'append bar'
create a second head
$ hg up -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo baz >> file
$ hg commit -Am 'append baz'
created new head
failing merge
$ hg merge --tool=internal:fail
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ echo resolved > file
$ hg resolve -m file
$ hg commit -m 'resolved'
resolve -l, should be empty
$ hg resolve -l
test crashed merge with empty mergestate
$ mkdir .hg/merge
$ touch .hg/merge/state
resolve -l, should be empty
$ hg resolve -l
$ cd ..