histedit: use revset to check if we need to update during abort

The for loop is already quite more complicated than necessary and we are about
to add some logic. Instead, we use a simple revset. Revset laziness should
provide us with similar performance.

hgext/histedit.py

@@ -791,11 +791,9 b' def _histedit(ui, repo, state, *freeargs'
             os.remove(backupfile)
 
         # check whether we should update away
-        parentnodes = [c.node() for c in repo[None].parents()]
-        for n in leafs | set([state.parentctxnode]):
-            if n in parentnodes:
-                hg.clean(repo, state.topmost)
-                break
+        if repo.unfiltered().revs('parents() and (%n  or %ln)',
+                                  state.parentctxnode, leafs):
+            hg.clean(repo, state.topmost)
         cleanupnode(ui, repo, 'created', tmpnodes)
         cleanupnode(ui, repo, 'temp', leafs)
         state.clear()