* newcomment.el (comment-search-backward): Stricter in finding

comment start. 

* progmodes/octave.el (octave-comment-start): Remove the SPC char.
(octave-comment-start-skip): Properly anchored.

Fixes: debbugs:14303

3 files changed, 35 insertions, 26 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 12ae5239f13..f07354cfe5d 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,13 @@
 2013-05-17  Leo Liu  <sdl.web@gmail.com>
 
+        * newcomment.el (comment-search-backward): Stricter in finding
+        comment start.  (Bug#14303)
+
+        * progmodes/octave.el (octave-comment-start): Remove the SPC char.
+        (octave-comment-start-skip): Properly anchored.
+
+2013-05-17  Leo Liu  <sdl.web@gmail.com>
+
         * emacs-lisp/smie.el (smie-highlight-matching-block-mode): Clean
         up when turned off.  (Bug#14395)
         (smie--highlight-matching-block-overlay): No longer buffer-local.
diff --git a/lisp/newcomment.el b/lisp/newcomment.el
index bcb5f721ae8..e10b96f97f9 100644
--- a/lisp/newcomment.el
+++ b/lisp/newcomment.el
@@ -485,27 +485,29 @@ and raises an error or returns nil if NOERROR is non-nil."
 Moves point to inside the comment and returns the position of the
 comment-starter.  If no comment is found, moves point to LIMIT
 and raises an error or returns nil if NOERROR is non-nil."
-  ;; FIXME: If a comment-start appears inside a comment, we may erroneously
-  ;; stop there.  This can be rather bad in general, but since
-  ;; comment-search-backward is only used to find the comment-column (in
-  ;; comment-set-column) and to find the comment-start string (via
-  ;; comment-beginning) in indent-new-comment-line, it should be harmless.
-  (if (not (re-search-backward comment-start-skip limit t))
-      (unless noerror (error "No comment"))
-    (beginning-of-line)
-    (let* ((end (match-end 0))
-           (cs (comment-search-forward end t))
-           (pt (point)))
-      (if (not cs)
-          (progn (beginning-of-line)
-                 (comment-search-backward limit noerror))
-        (while (progn (goto-char cs)
-                      (comment-forward)
-                      (and (< (point) end)
-                           (setq cs (comment-search-forward end t))))
-          (setq pt (point)))
-        (goto-char pt)
-        cs))))
+  (let (found end)
+    (while (and (not found)
+                (re-search-backward comment-start-skip limit t))
+      (setq end (match-end 0))
+      (unless (and comment-use-syntax
+                   (nth 8 (syntax-ppss (or (match-end 1)
+                                           (match-beginning 0)))))
+        (setq found t)))
+    (if (not found)
+        (unless noerror (error "No comment"))
+      (beginning-of-line)
+      (let ((cs (comment-search-forward end t))
+            (pt (point)))
+        (if (not cs)
+            (progn (beginning-of-line)
+                   (comment-search-backward limit noerror))
+          (while (progn (goto-char cs)
+                        (comment-forward)
+                        (and (< (point) end)
+                             (setq cs (comment-search-forward end t))))
+            (setq pt (point)))
+          (goto-char pt)
+          cs)))))
 
 (defun comment-beginning ()
   "Find the beginning of the enclosing comment.
diff --git a/lisp/progmodes/octave.el b/lisp/progmodes/octave.el
index 451ac2791a7..26fb254af5f 100644
--- a/lisp/progmodes/octave.el
+++ b/lisp/progmodes/octave.el
@@ -62,12 +62,11 @@ Used in `octave-mode' and `inferior-octave-mode' buffers.")
 (defvar octave-comment-char ?#
   "Character to start an Octave comment.")
 
-(defvar octave-comment-start
-  (string octave-comment-char ?\s)
-  "String to insert to start a new Octave in-line comment.")
+(defvar octave-comment-start (char-to-string octave-comment-char)
+  "Octave-specific `comment-start' (which see).")
 
-(defvar octave-comment-start-skip "\\(?:%!\\|\\s<+\\)\\s-*"
-  "Regexp to match the start of an Octave comment up to its body.")
+(defvar octave-comment-start-skip "\\(^\\|\\S<\\)\\(?:%!\\|\\s<+\\)\\s-*"
+  "Octave-specific `comment-start-skip' (which see).")
 
 (defvar octave-begin-keywords
   '("classdef" "do" "enumeration" "events" "for" "function" "if" "methods"