(Fdefvar): Don't try to set constant symbols.

2 files changed, 8 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 046d1a321fe..dcc8d0f2bd5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2005-06-27  Juanma Barranquero  <lekktu@gmail.com>
+
+        * eval.c (Fdefvar): Don't try to set constant symbols.
+
 2005-06-25  Richard M. Stallman  <rms@gnu.org>
 
         * macfns.c (Fx_show_tip): Pass new arg to try_window.
diff --git a/src/eval.c b/src/eval.c
index c33021da7b7..589bf593f15 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -806,6 +806,10 @@ usage: (defvar SYMBOL &optional INITVALUE DOCSTRING)  */)
   register Lisp_Object sym, tem, tail;
 
   sym = Fcar (args);
+  if (SYMBOL_CONSTANT_P (sym))
+    error ("Cannot defvar a constant symbol: %s",
+           SDATA (SYMBOL_NAME (sym)));
+
   tail = Fcdr (args);
   if (!NILP (Fcdr (Fcdr (tail))))
     error ("Too many arguments");