commitablectx: move bookmarks from workingctx

mercurial/context.py

@@ -1000,6 +1000,12 b' class commitablectx(basectx):'
             t.extend(p.tags())
         return t
 
+    def bookmarks(self):
+        b = []
+        for p in self.parents():
+            b.extend(p.bookmarks())
+        return b
+
 class workingctx(commitablectx):
     """A workingctx object makes access to data related to
     the current working directory convenient.
@@ -1026,12 +1032,6 b' class workingctx(commitablectx):'
             p = p[:-1]
         return [changectx(self._repo, x) for x in p]
 
-    def bookmarks(self):
-        b = []
-        for p in self.parents():
-            b.extend(p.bookmarks())
-        return b
-
     def phase(self):
         phase = phases.draft # default phase to draft
         for p in self.parents():