bookmarks: fix _bookmarks/lookup() reentrancy issue (issue2016)

_bookmarks is loaded lazily and calls super.lookup(). Unfortunately, branch and
tags caches initializations also recurse in lookup() and end up trying to
access _bookmarks again. Massive confusion ensues.

I considered fixing all branches and tags cache loading to avoid recursing in
lookup() but it would add complexity to otherwise working code provided lookups
are performed on nodes or revnums.

hgext/bookmarks.py

@@ -224,6 +224,7 b' def reposetup(ui, repo):'
             in the .hg/bookmarks file.
             Read the file and return a (name=>nodeid) dictionary
             '''
+            self._loadingbookmarks = True
             try:
                 bookmarks = {}
                 for line in self.opener('bookmarks'):
@@ -231,6 +232,7 b' def reposetup(ui, repo):'
                     bookmarks[refspec] = super(bookmark_repo, self).lookup(sha)
             except:
                 pass
+            self._loadingbookmarks = False
             return bookmarks
 
         @util.propertycache
@@ -257,8 +259,9 b' def reposetup(ui, repo):'
             return super(bookmark_repo, self).rollback(*args)
 
         def lookup(self, key):
-            if key in self._bookmarks:
-                key = self._bookmarks[key]
+            if not getattr(self, '_loadingbookmarks', False):
+                if key in self._bookmarks:
+                    key = self._bookmarks[key]
             return super(bookmark_repo, self).lookup(key)
 
         def _bookmarksupdate(self, parents, node):
@@ -357,7 +360,8 b' def reposetup(ui, repo):'
         def _findtags(self):
             """Merge bookmarks with normal tags"""
             (tags, tagtypes) = super(bookmark_repo, self)._findtags()
-            tags.update(self._bookmarks)
+            if not getattr(self, '_loadingbookmarks', False):
+                tags.update(self._bookmarks)
             return (tags, tagtypes)
 
         if hasattr(repo, 'invalidate'):

tests/test-bookmarks-strip

@@ -43,3 +43,18 b' hg strip 1 | hidebackup'
 echo % list bookmarks
 hg book
 
+echo '% test immediate rollback and reentrancy issue'
+echo "mq=!" >> $HGRCPATH
+hg init repo
+cd repo
+echo a > a
+hg ci -Am adda
+echo b > b
+hg ci -Am addb
+hg bookmarks markb
+hg rollback
+hg bookmarks
+hg bookmarks markb
+hg bookmarks
+cd ..
+

tests/test-bookmarks-strip.out

@@ -16,3 +16,9 b' saved backup bundle to'
 % list bookmarks
  * test                      1:9f1b7e78eff8
  * test2                     1:9f1b7e78eff8
+% test immediate rollback and reentrancy issue
+adding a
+adding b
+rolling back to revision 0 (undo commit)
+no bookmarks set
+ * markb                     0:07f494440405