Make read-char-by-name signal an error for invalid input.

* international/mule-cmds.el (read-char-by-name): Signal an error
if the user does not supply a valid character.

* editfns.c (Finsert_char): Since read-char-by-name now signals an
error for invalid chars, don't check for a nil return value.

Fixes: debbugs:13177

2 files changed, 15 insertions, 8 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index cd7dd97315b..a25836da996 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -5,6 +5,9 @@
 
 2012-12-21  Chong Yidong  <cyd@gnu.org>
 
+        * international/mule-cmds.el (read-char-by-name): Signal an error
+        if the user does not supply a valid character (Bug#13177).
+
         * simple.el (transpose-subr-1): Preserve marker positions by
         changing the insertion sequence (Bug#13122).
 
diff --git a/lisp/international/mule-cmds.el b/lisp/international/mule-cmds.el
index f324446fa74..07b0f911cb2 100644
--- a/lisp/international/mule-cmds.el
+++ b/lisp/international/mule-cmds.el
@@ -2953,14 +2953,18 @@ point or a number in hash notation, e.g. #o21430 for octal,
              (let ((completion-ignore-case t))
                (if (eq action 'metadata)
                    '(metadata (category . unicode-name))
-                 (complete-with-action action (ucs-names) string pred)))))))
-    (cond
-     ((string-match-p "\\`[0-9a-fA-F]+\\'" input)
-      (string-to-number input 16))
-     ((string-match-p "\\`#" input)
-      (read input))
-     (t
-      (cdr (assoc-string input (ucs-names) t))))))
+                 (complete-with-action action (ucs-names) string pred))))))
+         (char
+          (cond
+           ((string-match-p "\\`[0-9a-fA-F]+\\'" input)
+            (string-to-number input 16))
+           ((string-match-p "\\`#" input)
+            (read input))
+           (t
+            (cdr (assoc-string input (ucs-names) t))))))
+    (unless (characterp char)
+      (error "Invalid character"))
+    char))
 
 (define-obsolete-function-alias 'ucs-insert 'insert-char "24.3")
 (define-key ctl-x-map "8\r" 'insert-char)