diff -r fd598149112b -r 60b5db2ab586 mercurial/ui.py
--- a/mercurial/ui.py	Wed Feb 15 13:29:12 2017 -0800
+++ b/mercurial/ui.py	Wed Feb 15 13:38:00 2017 -0800
@@ -1139,7 +1139,8 @@
 
             self.system("%s \"%s\"" % (editor, name),
                         environ=environ,
-                        onerr=error.Abort, errprefix=_("edit failed"))
+                        onerr=error.Abort, errprefix=_("edit failed"),
+                        blockedtag='editor')
 
             f = open(name)
             t = f.read()