(substitute-key-definition): Avoid infinite recursion.

1 files changed, 12 insertions, 3 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 119e7c2159f..44a7e298e3c 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -133,6 +133,9 @@ but optional second arg NODIGITS non-nil treats them like other chars."
 ;      (copy-sequence keymap)
 ;      (copy-alist keymap)))
 
+(defvar key-substitution-in-progress nil
+ "Used internally by substitute-key-definition.")
+
 (defun substitute-key-definition (olddef newdef keymap &optional oldmap prefix)
   "Replace OLDDEF with NEWDEF for any keys in KEYMAP now defined as OLDDEF.
 In other words, OLDDEF is replaced with NEWDEF where ever it appears.
@@ -141,7 +144,9 @@ in KEYMAP as NEWDEF those chars which are defined as OLDDEF in OLDMAP."
   (or prefix (setq prefix ""))
   (let* ((scan (or oldmap keymap))
          (vec1 (vector nil))
-         (prefix1 (vconcat prefix vec1)))
+         (prefix1 (vconcat prefix vec1))
+         (key-substitution-in-progress
+          (cons scan key-substitution-in-progress)))
     ;; Scan OLDMAP, finding each char or event-symbol that
     ;; has any definition, and act on it with hack-key.
     (while (consp scan)
@@ -163,7 +168,9 @@ in KEYMAP as NEWDEF those chars which are defined as OLDDEF in OLDMAP."
                 (setq inner-def (symbol-function inner-def)))
               (if (eq defn olddef)
                   (define-key keymap prefix1 (nconc (nreverse skipped) newdef))
-                (if (keymapp defn)
+                (if (and (keymapp defn)
+                         (not (memq inner-def
+                                    key-substitution-in-progress)))
                     (substitute-key-definition olddef newdef keymap
                                                inner-def
                                                prefix1)))))
@@ -189,7 +196,9 @@ in KEYMAP as NEWDEF those chars which are defined as OLDDEF in OLDMAP."
                     (if (eq defn olddef)
                         (define-key keymap prefix1
                           (nconc (nreverse skipped) newdef))
-                      (if (keymapp defn)
+                      (if (and (keymapp defn)
+                               (not (memq inner-def
+                                          key-substitution-in-progress)))
                           (substitute-key-definition olddef newdef keymap
                                                      inner-def
                                                      prefix1)))))