From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Fri, 8 Jun 2012 02:47:26 +0000 (-0400)
Subject: * src/eval.c (Fmacroexpand): Stop if the macro returns the same form.
X-Git-Tag: emacs-24.2.90~1199^2~474^2~97
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=4f18a4ed84d7268090a92a194dcda40cae1197dd;p=emacs.git

* src/eval.c (Fmacroexpand): Stop if the macro returns the same form.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 3acf12e4483..e16da43761f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2012-06-08  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* eval.c (Fmacroexpand): Stop if the macro returns the same form.
+
 2012-06-07  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* doprnt.c (doprnt): Truncate multibyte char correctly.
diff --git a/src/eval.c b/src/eval.c
index 1da841a4073..85ff3ae19e6 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1020,7 +1020,13 @@ definitions to shadow the loaded ones for use in file byte-compilation.  */)
 	  if (NILP (expander))
 	    break;
 	}
-      form = apply1 (expander, XCDR (form));
+      {
+	Lisp_Object newform = apply1 (expander, XCDR (form));
+	if (EQ (form, newform))
+	  break;
+	else
+	  form = newform;
+      }
     }
   return form;
 }