(encoded-kbd-setup-display): Be careful not to remove keymaps that just

happen to inherit from one of ours.  When setting up our keymap, make sure
it won't be accidentally modified by someone else.

2 files changed, 64 insertions, 32 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 39daa6aef77..b92d3b1b654 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2007-10-18  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * international/encoded-kb.el (encoded-kbd-setup-display): Be careful
+        not to remove keymaps that just happen to inherit from one of ours.
+        When setting up our keymap, make sure it won't be accidentally
+        modified by someone else.
+
 2007-10-18  Thien-Thi Nguyen  <ttn@gnuvola.org>
 
         * textmodes/artist.el (artist-previous-line, artist-next-line):
diff --git a/lisp/international/encoded-kb.el b/lisp/international/encoded-kb.el
index 14c61560a41..5e690048aeb 100644
--- a/lisp/international/encoded-kb.el
+++ b/lisp/international/encoded-kb.el
@@ -262,38 +262,63 @@ DISPLAY may be a display id, a frame, or nil for the selected frame's display."
     (when frame
       (with-selected-frame frame
         ;; Remove any previous encoded-kb keymap from input-decode-map.
-        (let ((m input-decode-map))
-          (if (equal (keymap-prompt m) "encoded-kb")
-              (setq input-decode-map (keymap-parent m))
-            (while (keymap-parent m)
-              (if (equal (keymap-prompt (keymap-parent m)) "encoded-kb")
-                  (set-keymap-parent m (keymap-parent (keymap-parent m))))
-              (setq m (keymap-parent m)))))
-
-        (if (keyboard-coding-system)
-            ;; We are turning on Encoded-kbd mode.
-            (let ((coding (keyboard-coding-system))
-                  (keymap (make-sparse-keymap "encoded-kb"))
-                  (cim (current-input-mode))
-                  result)
-              (set-keymap-parent keymap input-decode-map)
-              (setq input-decode-map keymap)
-              (unless (terminal-parameter nil 'encoded-kbd-saved-input-meta-mode)
-                (set-terminal-parameter nil 'encoded-kbd-saved-input-mode (nth 2 cim)))
-              (setq result (and coding (encoded-kbd-setup-keymap keymap coding)))
-              (if result
-                  (when (and (eq result 8)
-                             (memq (nth 2 cim) '(t nil)))
-                    (set-input-meta-mode 'use-8th-bit))
-                (set-terminal-parameter nil 'encoded-kbd-saved-input-meta-mode nil)
-                (error "Unsupported coding system in Encoded-kbd mode: %S"
-                       coding)))
-          ;; We are turning off Encoded-kbd mode.
-          (when (and (terminal-parameter nil 'encoded-kbd-saved-input-meta-mode)
-                     (not (equal (nth 2 (current-input-mode))
-                                 (terminal-parameter nil 'encoded-kbd-saved-input-meta-mode))))
-            (set-input-meta-mode (terminal-parameter nil 'encoded-kbd-saved-input-meta-mode)))
-          (set-terminal-parameter nil 'saved-input-meta-mode nil))))))
+        (let ((m input-decode-map)
+              (child nil))
+          (while (keymapp m)
+            (if (not (equal (keymap-prompt m) "encoded-kb"))
+                (progn
+                  (setq child m)
+                  (setq m (keymap-parent m)))
+              ;; We've found an encoded-kb map, but maybe the prompt we get
+              ;; is really inherited from the encoded-kb map.
+              (let (mp)
+                (while (and (keymapp (setq mp (keymap-parent m)))
+                            (equal (keymap-prompt mp) "encoded-kb"))
+                  (setq child m)
+                  (setq m mp))
+                ;; (assert (equal (keymap-prompt m) "encoded-kb"))
+                ;; (assert (eq mp (keymap-parent m)))
+                ;; (assert (not (and (keymapp mp)
+                ;;                   (equal (keymap-prompt mp) "encoded-kb"))))
+                ;; (assert (eq m (if child
+                ;;                   (keymap-parent child) input-decode-map)))
+                ;; We can finally do the actual removal.
+                (if child
+                    (set-keymap-parent child mp)
+                  (setq input-decode-map mp))
+                (setq m mp))))))
+
+      (if (keyboard-coding-system)
+          ;; We are turning on Encoded-kbd mode.
+          (let ((coding (keyboard-coding-system))
+                (keymap (make-sparse-keymap "encoded-kb"))
+                (cim (current-input-mode))
+                result)
+            ;; Place `keymap' as the immediate parent of input-decode-map
+            ;; rather than on top, so that later `define-key' on
+            ;; input-decode-map don't end up accidentally changing our
+            ;; part of the keymap, which would lead to bugs when/if we later
+            ;; on remove that part.
+            (set-keymap-parent keymap (keymap-parent input-decode-map))
+            (set-keymap-parent input-decode-map keymap)
+            (unless (terminal-parameter nil 'encoded-kbd-saved-input-meta-mode)
+              (set-terminal-parameter nil 'encoded-kbd-saved-input-mode
+                                      (nth 2 cim)))
+            (setq result (and coding (encoded-kbd-setup-keymap keymap coding)))
+            (if result
+                (when (and (eq result 8)
+                           (memq (nth 2 cim) '(t nil)))
+                  (set-input-meta-mode 'use-8th-bit))
+              (set-terminal-parameter
+               nil 'encoded-kbd-saved-input-meta-mode nil)
+              (error "Unsupported coding system in Encoded-kbd mode: %S"
+                     coding)))
+        ;; We are turning off Encoded-kbd mode.
+        (let ((old (terminal-parameter nil 'encoded-kbd-saved-input-meta-mode)))
+          (when (and old (not (equal (nth 2 (current-input-mode)) old)))
+            (set-input-meta-mode old))
+          (set-terminal-parameter
+           nil 'encoded-kbd-saved-input-meta-mode nil))))))
 
 (provide 'encoded-kb)