--- a/mercurial/commands.py	Thu May 11 10:14:48 2006 -0700
+++ b/mercurial/commands.py	Thu May 11 14:46:24 2006 -0700
@@ -789,6 +789,7 @@
     commit_opts['addremove'] = False
     if not commit_opts['message'] and not commit_opts['logfile']:
         commit_opts['message'] = _("Backed out changeset %s") % (hex(node))
+        commit_opts['force_editor'] = True
     commit(ui, repo, **commit_opts)
     def nice(node):
         return '%d:%s' % (repo.changelog.rev(node), short(node))
@@ -987,7 +988,8 @@
     else:
         files = []
     try:
-        repo.commit(files, message, opts['user'], opts['date'], match)
+        repo.commit(files, message, opts['user'], opts['date'], match,
+                    force_editor=opts.get('force_editor'))
     except ValueError, inst:
         raise util.Abort(str(inst))
 

--- a/mercurial/localrepo.py	Thu May 11 10:14:48 2006 -0700
+++ b/mercurial/localrepo.py	Thu May 11 14:46:24 2006 -0700
@@ -446,7 +446,8 @@
             self.dirstate.setparents(n, nullid)
 
     def commit(self, files=None, text="", user=None, date=None,
-               match=util.always, force=False, lock=None, wlock=None):
+               match=util.always, force=False, lock=None, wlock=None,
+               force_editor=False):
         commit = []
         remove = []
         changed = []
@@ -535,8 +536,11 @@
         new.sort()
 
         user = user or self.ui.username()
-        if not text:
-            edittext = [""]
+        if not text or force_editor:
+            edittext = []
+            if text:
+                edittext.append(text)
+            edittext.append("")
             if p2 != nullid:
                 edittext.append("HG: branch merge")
             edittext.extend(["HG: changed %s" % f for f in changed])

--- a/tests/test-backout.out	Thu May 11 10:14:48 2006 -0700
+++ b/tests/test-backout.out	Thu May 11 14:46:24 2006 -0700
@@ -1,19 +1,19 @@
 # basic operation
 adding a
-changeset 2:b38a34ddfd9f backs out changeset 1:a820f4f40a57
+changeset 2:c86754337410 backs out changeset 1:a820f4f40a57
 a
 # file that was removed is recreated
 adding a
 adding a
-changeset 2:44cd84c7349a backs out changeset 1:76862dcce372
+changeset 2:d2d961bd79f2 backs out changeset 1:76862dcce372
 content
 # backout of backout is as if nothing happened
 removing a
-changeset 3:0dd8a0ed5e99 backs out changeset 2:44cd84c7349a
+changeset 3:8a7eeb5ab5ce backs out changeset 2:d2d961bd79f2
 cat: a: No such file or directory
 # backout with merge
 adding a
-changeset 3:6c77ecc28460 backs out changeset 1:314f55b1bf23
+changeset 3:3c9e845b409c backs out changeset 1:314f55b1bf23
 merging with changeset 2:b66ea5b77abb
 merging a
 0 files updated, 1 files merged, 0 files removed, 0 files unresolved