Fix non-prefix key error message when last character M-[char] is translated to ESC [char]

2 files changed, 26 insertions, 7 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 80508531b1a..858833dbe25 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2010-12-03  Don March  <don@ohspite.net>
+
+        * keymap.c (Fdefine_key): Fix non-prefix key error message when
+        last character M-[char] is translated to ESC [char] (bug#7541).
+
 2011-08-02  Kenichi Handa  <handa@m17n.org>
 
         * lisp.h (uniprop_table): Extern it.
diff --git a/src/keymap.c b/src/keymap.c
index 0169276bef9..03688abfe4c 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -1216,13 +1216,27 @@ binding KEY to DEF is added at the front of KEYMAP.  */)
 
       keymap = get_keymap (cmd, 0, 1);
       if (!CONSP (keymap))
-        /* We must use Fkey_description rather than just passing key to
-           error; key might be a vector, not a string.  */
-        error ("Key sequence %s starts with non-prefix key %s",
-               SDATA (Fkey_description (key, Qnil)),
-               SDATA (Fkey_description (Fsubstring (key, make_number (0),
-                                                    make_number (idx)),
-                                        Qnil)));
+        {
+          char trailing_esc[5];
+          if (c == meta_prefix_char && metized)
+            {
+              if (idx == 0)
+                strcpy(trailing_esc, "ESC");
+              else
+                strcpy(trailing_esc, " ESC");
+            }
+          else
+              strcpy(trailing_esc, "");
+
+          /* We must use Fkey_description rather than just passing key to
+             error; key might be a vector, not a string.  */
+          error ("Key sequence %s starts with non-prefix key %s%s",
+                 SDATA (Fkey_description (key, Qnil)),
+                 SDATA (Fkey_description (Fsubstring (key, make_number (0),
+                                                      make_number (idx)),
+                                          Qnil)),
+                 trailing_esc);
+        }
     }
 }