Avoid signaling errors in lookup-key

* src/keymap.c (Flookup_key): Handle KEY vectors where not all
components are symbols.  (Bug#51527

1 files changed, 39 insertions, 27 deletions

diff --git a/src/keymap.c b/src/keymap.c
index 5ff13ba1d57..08f37dbd8b5 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -1314,36 +1314,44 @@ recognize the default bindings, just as `read-key-sequence' does.  */)
          "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 @@ recognize the default bindings, just as `read-key-sequence' does.  */)
          "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.  */
@@ -1378,8 +1389,9 @@ recognize the default bindings, just as `read-key-sequence' does.  */)
               if (dst[i] == ' ')
                 dst[i] = '-';
             }
-          Lisp_Object
-            new_it = make_multibyte_string ((char *) dst, SCHARS (lc_key), SBYTES (lc_key));
+          Lisp_Object new_it =
+            make_multibyte_string ((char *) dst,
+                                   SCHARS (lc_key), SBYTES (lc_key));
           ASET (new_key, i, Fintern (new_it, Qnil));
           SAFE_FREE ();
         }