bug#51527: 29.0.50; (wrong-type-argument symbolp 1) lookup-key((keymap) [menu-bar buffer 1])

[Eli Zaretskii]

> From: Dieter Deyke <dieter.deyke@gmail.com>
> Date: Sun, 31 Oct 2021 08:22:56 +0100
> 
> 
> Using emacs -Q (build from git master) works fine. Starting it with my
> customizations fails:
> 
> Debugger entered--Lisp error: (wrong-type-argument symbolp 1)
>   lookup-key((keymap) [menu-bar buffer 1])
>   substitute-key-definition-key(("Most recently used (1)" keymap "Most 
> recently used (1)" ("*Messages*" "*% *Messages*" . msb--select-buffer)) 
> beginning-of-line allout-beginning-of-line [menu-bar buffer 1] (keymap))

Thanks.

Does the patch below fix this?

diff --git a/src/keymap.c b/src/keymap.c
index 5ff13ba..4d8944d 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -1314,36 +1314,44 @@ DEFUN ("lookup-key", Flookup_key, Slookup_key, 2, 3, 0,
         "foo-bar-baz".  */
       for (int i = 0; i < key_len; i++)
        {
-         Lisp_Object key_item = Fsymbol_name (AREF (key, i));
-         Lisp_Object new_item;
-         if (!STRING_MULTIBYTE (key_item))
-           new_item = Fdowncase (key_item);
+         Lisp_Object item = AREF (key, i);
+         if (!SYMBOLP (item))
+           ASET (new_key, i, item);
          else
            {
-             USE_SAFE_ALLOCA;
-             ptrdiff_t size = SCHARS (key_item), n;
-             if (INT_MULTIPLY_WRAPV (size, MAX_MULTIBYTE_LENGTH, &n))
-               n = PTRDIFF_MAX;
-             unsigned char *dst = SAFE_ALLOCA (n);
-             unsigned char *p = dst;
-             ptrdiff_t j_char = 0, j_byte = 0;
-
-             while (j_char < size)
+             Lisp_Object key_item = Fsymbol_name (item);
+             Lisp_Object new_item;
+             if (!STRING_MULTIBYTE (key_item))
+               new_item = Fdowncase (key_item);
+             else
                {
-                 int ch = fetch_string_char_advance (key_item, &j_char, 
&j_byte);
-                 Lisp_Object ch_conv = CHAR_TABLE_REF (tables[tbl_num], ch);
-                 if (!NILP (ch_conv))
-                   CHAR_STRING (XFIXNUM (ch_conv), p);
-                 else
-                   CHAR_STRING (ch, p);
-                 p = dst + j_byte;
+                 USE_SAFE_ALLOCA;
+                 ptrdiff_t size = SCHARS (key_item), n;
+                 if (INT_MULTIPLY_WRAPV (size, MAX_MULTIBYTE_LENGTH, &n))
+                   n = PTRDIFF_MAX;
+                 unsigned char *dst = SAFE_ALLOCA (n);
+                 unsigned char *p = dst;
+                 ptrdiff_t j_char = 0, j_byte = 0;
+
+                 while (j_char < size)
+                   {
+                     int ch = fetch_string_char_advance (key_item,
+                                                         &j_char, &j_byte);
+                     Lisp_Object ch_conv = CHAR_TABLE_REF (tables[tbl_num],
+                                                           ch);
+                     if (!NILP (ch_conv))
+                       CHAR_STRING (XFIXNUM (ch_conv), p);
+                     else
+                       CHAR_STRING (ch, p);
+                     p = dst + j_byte;
+                   }
+                 new_item = make_multibyte_string ((char *) dst,
+                                                   SCHARS (key_item),
+                                                   SBYTES (key_item));
+                 SAFE_FREE ();
                }
-             new_item = make_multibyte_string ((char *) dst,
-                                               SCHARS (key_item),
-                                               SBYTES (key_item));
-             SAFE_FREE ();
+             ASET (new_key, i, Fintern (new_item, Qnil));
            }
-         ASET (new_key, i, Fintern (new_item, Qnil));
        }
 
       /* Check for match.  */
@@ -1356,6 +1364,9 @@ DEFUN ("lookup-key", Flookup_key, Slookup_key, 2, 3, 0,
         "foo-bar-baz".  */
       for (int i = 0; i < key_len; i++)
        {
+         if (!SYMBOLP (AREF (new_key, i)))
+           continue;
+
          Lisp_Object lc_key = Fsymbol_name (AREF (new_key, i));
 
          /* If there are no spaces in this symbol, just skip it.  */