Do not allow to set major mode for a dead buffer.

* buffer.c (Fset_buffer_major_mode): Signal an error
if the buffer is dead.
(Fother_buffer, other_buffer_safely): Remove redundant
nested declaration.

src/ChangeLog

+2012-08-28  Dmitry Antipov  <dmantipov@yandex.ru>
+
+	Do not allow to set major mode for a dead buffer.
+	* buffer.c (Fset_buffer_major_mode): Signal an error
+	if the buffer is dead.
+	(Fother_buffer, other_buffer_safely): Remove redundant
+	nested declaration.
+
 2012-08-28  Dmitry Antipov  <dmantipov@yandex.ru>
 
 	Always use set_buffer_if_live to restore original buffer at unwind.

src/buffer.c

@@ -1553,7 +1553,6 @@ list first, followed by the list of all buffers.  If no other buffer
 exists, return the buffer `*scratch*' (creating it if necessary).  */)
   (register Lisp_Object buffer, Lisp_Object visible_ok, Lisp_Object frame)
 {
-  Lisp_Object Fset_buffer_major_mode (Lisp_Object buffer);
   Lisp_Object tail, buf, pred;
   Lisp_Object notsogood = Qnil;
 
@@ -1624,7 +1623,6 @@ exists, return the buffer `*scratch*' (creating it if necessary).  */)
 Lisp_Object
 other_buffer_safely (Lisp_Object buffer)
 {
-  Lisp_Object Fset_buffer_major_mode (Lisp_Object buffer);
   Lisp_Object tail, buf;
 
   tail = Vbuffer_alist;
@@ -2064,8 +2062,10 @@ the current buffer's major mode.  */)
 
   CHECK_BUFFER (buffer);
 
-  if (STRINGP (BVAR (XBUFFER (buffer), name))
-      && strcmp (SSDATA (BVAR (XBUFFER (buffer), name)), "*scratch*") == 0)
+  if (NILP (BVAR (XBUFFER (buffer), name)))
+    error ("Attempt to set major mode for a dead buffer");
+
+  if (strcmp (SSDATA (BVAR (XBUFFER (buffer), name)), "*scratch*") == 0)
     function = find_symbol_value (intern ("initial-major-mode"));
   else
     {