revisionbranchcache: fall back to slow path if starting readonly (issue4531)
Transitioning to Mercurial versions with revision branch cache could be slow as
long as all operations were readonly (revset queries) and the cache would be
populated but not written back.
Instead, fall back to using the consistently slow path when readonly and the
cache doesn't exist yet. That avoids the overhead of populating the cache
without writing it back.
If not readonly, it will still populate all missing entries initially. That
avoids repeated writing of the cache file with small updates, and it also makes
sure a fully populated cache available for the readonly operations.
$ hg init
$ echo foo > foo
$ echo bar > bar
$ hg ci -qAm 'add foo bar'
$ echo foo2 >> foo
$ echo bleh > bar
$ hg ci -m 'change foo bar'
$ hg up -qC 0
$ hg mv foo foo1
$ echo foo1 > foo1
$ hg cat foo >> foo1
$ hg ci -m 'mv foo foo1'
created new head
$ hg merge
merging foo1 and foo to foo1
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg debugstate --nodates
m 0 -2 unset bar
m 0 -2 unset foo1
copy: foo -> foo1
$ hg st -q
M bar
M foo1
Removing foo1 and bar:
$ cp foo1 F
$ cp bar B
$ hg rm -f foo1 bar
$ hg debugstate --nodates
r 0 -1 set bar
r 0 -1 set foo1
copy: foo -> foo1
$ hg st -qC
R bar
R foo1
Re-adding foo1 and bar:
$ cp F foo1
$ cp B bar
$ hg add -v foo1 bar
adding bar
adding foo1
$ hg debugstate --nodates
n 0 -2 unset bar
n 0 -2 unset foo1
copy: foo -> foo1
$ hg st -qC
M bar
M foo1
foo
Reverting foo1 and bar:
$ hg revert -vr . foo1 bar
saving current version of bar as bar.orig
reverting bar
saving current version of foo1 as foo1.orig
reverting foo1
$ hg debugstate --nodates
n 0 -2 unset bar
n 0 -2 unset foo1
copy: foo -> foo1
$ hg st -qC
M bar
M foo1
foo
$ hg diff
Merge should not overwrite local file that is untracked after remove
$ rm *
$ hg up -qC
$ hg rm bar
$ hg ci -m 'remove bar'
$ echo 'memories of buried pirate treasure' > bar
$ hg merge
bar: untracked file differs
abort: untracked files in working directory differ from files in requested revision
[255]
$ cat bar
memories of buried pirate treasure
Those who use force will lose
$ hg merge -f
remote changed bar which local deleted
use (c)hanged version or leave (d)eleted? c
merging foo1 and foo to foo1
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ cat bar
bleh
$ hg st
M bar
M foo1