localrepo: restore dirstate to one before rollbacking if not parent-gone
'localrepository.rollback()' explicilty restores dirstate, only if at
least one of current parents of the working directory is removed at
rollbacking (a.k.a "parent-gone").
After DirstateTransactionPlan, 'dirstate.write()' will cause marking
'.hg/dirstate' as a file to be restored at rollbacking.
https://mercurial.selenic.com/wiki/DirstateTransactionPlan
Then, 'transaction.rollback()' restores '.hg/dirstate' regardless of
parents of the working directory at that time, and this causes
unexpected dirstate changes if not "parent-gone" (e.g. "hg update" to
another branch after "hg commit" or so, then "hg rollback").
To avoid such situation, this patch restores dirstate to one before
rollbacking if not "parent-gone".
before:
b1. restore dirstate explicitly, if "parent-gone"
after:
a1. save dirstate before actual rollbacking via dirstateguard
a2. restore dirstate via 'transaction.rollback()'
a3. if "parent-gone"
- discard backup (a1)
- restore dirstate from 'undo.dirstate'
a4. otherwise, restore dirstate from backup (a1)
Even though restoring dirstate at (a3) after (a2) seems redundant,
this patch keeps this existing code path, because:
- it isn't ensured that 'dirstate.write()' was invoked at least once
while transaction running
If not, '.hg/dirstate' isn't restored at (a2).
In addition to it, rude 3rd party extension invoking
'dirstate.write()' without 'repo' while transaction running (see
subsequent patches for detail) may break consistency of a file
backup-ed by transaction.
- this patch mainly focuses on changes for DirstateTransactionPlan
Restoring dirstate at (a3) itself should be cheaper enough than
rollbacking itself. Redundancy will be removed in next step.
Newly added test is almost meaningless at this point. It will be used
to detect regression while implementing delayed dirstate write out.
--- a/mercurial/localrepo.py Wed Oct 14 02:40:04 2015 +0900
+++ b/mercurial/localrepo.py Tue Oct 13 12:25:43 2015 -0700
@@ -11,7 +11,7 @@
import changelog, dirstate, filelog, manifest, context, bookmarks, phases
import lock as lockmod
import transaction, store, encoding, exchange, bundle2
-import scmutil, util, extensions, hook, error, revset
+import scmutil, util, extensions, hook, error, revset, cmdutil
import match as matchmod
import merge as mergemod
import tags as tagsmod
@@ -1084,20 +1084,22 @@
lock.release()
def rollback(self, dryrun=False, force=False):
- wlock = lock = None
+ wlock = lock = dsguard = None
try:
wlock = self.wlock()
lock = self.lock()
if self.svfs.exists("undo"):
- return self._rollback(dryrun, force)
+ dsguard = cmdutil.dirstateguard(self, 'rollback')
+
+ return self._rollback(dryrun, force, dsguard)
else:
self.ui.warn(_("no rollback information available\n"))
return 1
finally:
- release(lock, wlock)
+ release(dsguard, lock, wlock)
@unfilteredmethod # Until we get smarter cache management
- def _rollback(self, dryrun, force):
+ def _rollback(self, dryrun, force, dsguard):
ui = self.ui
try:
args = self.vfs.read('undo.desc').splitlines()
@@ -1140,6 +1142,9 @@
parentgone = (parents[0] not in self.changelog.nodemap or
parents[1] not in self.changelog.nodemap)
if parentgone:
+ # prevent dirstateguard from overwriting already restored one
+ dsguard.close()
+
self.vfs.rename('undo.dirstate', 'dirstate')
try:
branch = self.vfs.read('undo.branch')
--- a/tests/test-import.t Wed Oct 14 02:40:04 2015 +0900
+++ b/tests/test-import.t Tue Oct 13 12:25:43 2015 -0700
@@ -428,6 +428,25 @@
working directory now based on revision 0
$ hg --cwd b parents --template 'parent: {rev}\n'
parent: 0
+
+Test that "hg rollback" doesn't restore dirstate to one at the
+beginning of the rollbacked transaction in not-"parent-gone" case.
+
+invoking pretxncommit hook will cause marking '.hg/dirstate' as a file
+to be restored at rollbacking, after DirstateTransactionPlan (see wiki
+page for detail).
+
+ $ hg --cwd b branch -q foobar
+ $ hg --cwd b commit -m foobar
+ $ hg --cwd b update 0 -q
+ $ hg --cwd b import ../patch1 ../patch2 --config hooks.pretxncommit=true
+ applying ../patch1
+ applying ../patch2
+ $ hg --cwd b update -q 1
+ $ hg --cwd b rollback -q
+ $ hg --cwd b parents --template 'parent: {rev}\n'
+ parent: 1
+
$ rm -r b