mq: wrap the dirstate's rebuild in a `changing_parents` context

This code is dealing with `qreshesh` failure. In that case the working copy
will be left on the parent of the refreshed patch, so the parents are changing
and `changing_parents` make sens.

hgext/mq.py

@@ -2121,9 +2121,9 b' class queue:'
                 finally:
                     lockmod.release(tr, lock)
             except:  # re-raises
-                ctx = repo[cparents[0]]
-                repo.dirstate.rebuild(ctx.node(), ctx.manifest())
-                repo.dirstate.write(repo.currenttransaction())
+                with repo.dirstate.changing_parents(repo):
+                    ctx = repo[cparents[0]]
+                    repo.dirstate.rebuild(ctx.node(), ctx.manifest())
                 self.savedirty()
                 self.ui.warn(
                     _(