(read_key_sequence): Don't downshift an event

if that fails to make it bound.
(follow_key): Don't alter contents of NEXT until the end.

diff --git a/src/keyboard.c b/src/keyboard.c
index 2810ec0b02bd44058cce70b48f8a2e160e81dc74..fa0f4bdce37be6595e01251addeab59b35399545 100644 (file)
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -4998,7 +4998,7 @@ read_char_minibuf_menu_prompt (commandflag, nmaps, maps)
    If KEY has no bindings in any of the CURRENT maps, NEXT is left
    unmodified.
 
-   NEXT may == CURRENT.  */
+   NEXT may be the same array as CURRENT.  */
 
 static int
 follow_key (key, nmaps, current, defs, next)
@@ -5007,26 +5007,30 @@ follow_key (key, nmaps, current, defs, next)
      int nmaps;
 {
   int i, first_binding;
+  int did_meta = 0;
 
   /* If KEY is a meta ASCII character, treat it like meta-prefix-char
-     followed by the corresponding non-meta character.  */
+     followed by the corresponding non-meta character.
+     Put the results into DEFS, since we are going to alter that anyway.
+     Do not alter CURRENT or NEXT.  */
   if (INTEGERP (key) && (XINT (key) & CHAR_META))
     {
       for (i = 0; i < nmaps; i++)
        if (! NILP (current[i]))
          {
-           next[i] =
-             get_keyelt (access_keymap (current[i], meta_prefix_char, 1, 0));
+           Lisp_Object def;
+           def = get_keyelt (access_keymap (current[i],
+                                            meta_prefix_char, 1, 0));
 
            /* Note that since we pass the resulting bindings through
               get_keymap_1, non-prefix bindings for meta-prefix-char
               disappear.  */
-           next[i] = get_keymap_1 (next[i], 0, 1);
+           defs[i] = get_keymap_1 (def, 0, 1);
          }
        else
-         next[i] = Qnil;
+         defs[i] = Qnil;
 
-      current = next;
+      did_meta = 1;
       XSETINT (key, XFASTINT (key) & ~CHAR_META);
     }
 
@@ -5035,7 +5039,13 @@ follow_key (key, nmaps, current, defs, next)
     {
       if (! NILP (current[i]))
        {
-         defs[i] = get_keyelt (access_keymap (current[i], key, 1, 0));
+         Lisp_Object map;
+         if (did_meta)
+           map = defs[i];
+         else
+           map = current[i];
+
+         defs[i] = get_keyelt (access_keymap (map, key, 1, 0));
          if (! NILP (defs[i]))
            first_binding = i;
        }
@@ -5956,18 +5966,35 @@ read_key_sequence (keybuf, bufsize, prompt, dont_downcase_last,
               && UPPERCASEP (XINT (key) & 0x3ffff))
              || (XINT (key) & shift_modifier)))
        {
+         Lisp_Object new_key;
+         int new_first_binding;
+
          original_uppercase = key;
          original_uppercase_position = t - 1;
 
-         if (XINT (key) & shift_modifier)
-           XSETINT (key, XINT (key) & ~shift_modifier);
+         if (XINT (new_key) & shift_modifier)
+           XSETINT (new_key, XINT (key) & ~shift_modifier);
          else
-           XSETINT (key, (DOWNCASE (XINT (key) & 0x3ffff)
-                          | (XINT (key) & ~0x3ffff)));
-
-         keybuf[t - 1] = key;
-         mock_input = t;
-         goto replay_sequence;
+           XSETINT (new_key, (DOWNCASE (XINT (key) & 0x3ffff)
+                              | (XINT (key) & ~0x3ffff)));
+
+         /* See if new_key has a binding.
+            If it does not have one, this does not alter SUBMAPS.  */
+         new_first_binding
+           = (follow_key (new_key,
+                          nmaps   - local_first_binding,
+                          submaps + local_first_binding,
+                          defs    + local_first_binding,
+                          submaps + local_first_binding)
+              + local_first_binding);
+
+         /* If that lower-case char is bound, use it instead.  */
+         if (new_first_binding < nmaps)
+           {
+             keybuf[t - 1] = new_key;
+             mock_input = t;
+             goto replay_sequence;
+           }
        }
       /* If KEY is not defined in any of the keymaps,
         and cannot be part of a function key or translation,
@@ -5987,13 +6014,30 @@ read_key_sequence (keybuf, bufsize, prompt, dont_downcase_last,
          modifiers = XINT (XCONS (XCONS (breakdown)->cdr)->car);
          if (modifiers & shift_modifier)
            {
-             modifiers &= ~shift_modifier;
-             key = apply_modifiers (modifiers,
-                                    XCONS (breakdown)->car);
+             Lisp_Object new_key;
+             int new_first_binding;
 
-             keybuf[t - 1] = key;
-             mock_input = t;
-             goto replay_sequence;
+             modifiers &= ~shift_modifier;
+             new_key = apply_modifiers (modifiers,
+                                        XCONS (breakdown)->car);
+
+             /* See if new_key has a binding.
+                If it does not have one, this does not alter SUBMAPS.  */
+             new_first_binding
+               = (follow_key (new_key,
+                              nmaps   - local_first_binding,
+                              submaps + local_first_binding,
+                              defs    + local_first_binding,
+                              submaps + local_first_binding)
+                  + local_first_binding);
+
+             /* If that unshifted key is bound, use it instead.  */
+             if (new_first_binding < nmaps)
+               {
+                 keybuf[t - 1] = new_key;
+                 mock_input = t;
+                 goto replay_sequence;
+               }
            }
        }
     }