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

1 files changed, 7 insertions, 1 deletions

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;
 }