* lisp/progmodes/subword.el (subword-capitalize): Be careful when

the search for [[:alpha:]] fails.

Fixes: debbugs:15580

1 files changed, 19 insertions, 18 deletions

diff --git a/lisp/progmodes/subword.el b/lisp/progmodes/subword.el
index 8cf4feb62cb..1232588ca32 100644
--- a/lisp/progmodes/subword.el
+++ b/lisp/progmodes/subword.el
@@ -257,24 +257,25 @@ Optional argument ARG is the same as for `upcase-word'."
 See the command `subword-mode' for a description of subwords.
 Optional argument ARG is the same as for `capitalize-word'."
   (interactive "p")
-  (let ((count (abs arg))
-        (start (point))
-        (advance (if (< arg 0) nil t)))
-    (dotimes (i count)
-      (if advance
-          (progn (re-search-forward
-                  (concat "[[:alpha:]]")
-                  nil t)
-                 (goto-char (match-beginning 0)))
-        (subword-backward))
-      (let* ((p (point))
-             (pp (1+ p))
-             (np (subword-forward)))
-        (upcase-region p pp)
-        (downcase-region pp np)
-        (goto-char (if advance np p))))
-    (unless advance
-      (goto-char start))))
+  (catch 'search-failed
+    (let ((count (abs arg))
+          (start (point))
+          (advance (>= arg 0)))
+
+      (dotimes (i count)
+        (if advance
+            (progn
+              (search-forward "[[:alpha:]]")
+              (goto-char (match-beginning 0)))
+          (subword-backward))
+        (let* ((p (point))
+               (pp (1+ p))
+               (np (subword-forward)))
+          (upcase-region p pp)
+          (downcase-region pp np)
+          (goto-char (if advance np p))))
+      (unless advance
+        (goto-char start)))))