diff -r bc475d1f74ca -r 6183df642f95 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Fri Dec 28 00:03:55 2007 -0600
+++ b/mercurial/localrepo.py	Fri Dec 28 16:32:14 2007 +0100
@@ -799,6 +799,8 @@
                 if text:
                     edittext.append(text)
                 edittext.append("")
+                edittext.append(_("HG: Please write and save a commit message"))
+                edittext.append("HG: --")
                 edittext.append("HG: user: %s" % user)
                 if p2 != nullid:
                     edittext.append("HG: branch merge")
@@ -823,7 +825,7 @@
                 while lines and not lines[0]:
                     del lines[0]
                 if not lines:
-                    return None
+                    raise util.Abort(_("commit message cannot be left blank"))
                 text = '\n'.join(lines)
 
             n = self.changelog.add(mn, changed + removed, text, trp, p1, p2,