[Emacs-diffs] trunk r116790: Further tweaks for comment-start-skip behavior

[Dmitry Gutov]

------------------------------------------------------------
revno: 116790
revision-id: address@hidden
parent: address@hidden
fixes bug: http://debbugs.gnu.org/16971
committer: Dmitry Gutov <address@hidden>
branch nick: trunk
timestamp: Tue 2014-03-18 08:06:33 +0200
message:
  Further tweaks for comment-start-skip behavior
  
  * lisp/newcomment.el (comment-normalize-vars): Only add escaping check
  to `comment-start-skip' if not `comment-use-syntax'. 
  (comment-beginning): Use `narrow-to-region' instead of moving back
  one character.
  (http://lists.gnu.org/archive/html/emacs-devel/2014-03/msg00488.html)
  (comment-start-skip): Update the docstring.
modified:
  lisp/ChangeLog                 changelog-20091113204419-o5vbwnq5f7feedwu-1432
  lisp/newcomment.el             
newcomment.el-20091113204419-o5vbwnq5f7feedwu-1719

=== modified file 'lisp/ChangeLog'
--- a/lisp/ChangeLog    2014-03-18 01:51:12 +0000
+++ b/lisp/ChangeLog    2014-03-18 06:06:33 +0000
@@ -1,3 +1,12 @@
+2014-03-18  Dmitry Gutov  <address@hidden>
+
+       * newcomment.el (comment-normalize-vars): Only add escaping check
+       to `comment-start-skip' if not `comment-use-syntax'.  (Bug#16971)
+       (comment-beginning): Use `narrow-to-region' instead of moving back
+       one character.
+       (http://lists.gnu.org/archive/html/emacs-devel/2014-03/msg00488.html)
+       (comment-start-skip): Update the docstring.
+
 2014-03-18  Daniel Colascione  <address@hidden>
 
        * startup.el (tty-handle-args): Remove debug message from 2007.

=== modified file 'lisp/newcomment.el'
--- a/lisp/newcomment.el        2014-03-17 06:48:09 +0000
+++ b/lisp/newcomment.el        2014-03-18 06:06:33 +0000
@@ -120,8 +120,9 @@
 ;;;###autoload
 (defvar comment-start-skip nil
   "Regexp to match the start of a comment plus everything up to its body.
-If there are any \\(...\\) pairs, the comment delimiter text is held to begin
-at the place matched by the close of the first pair.")
+If there are any \\(...\\) pairs and `comment-use-syntax' is nil,
+the comment delimiter text is held to begin at the place matched
+by the close of the first pair.")
 ;;;###autoload
 (put 'comment-start-skip 'safe-local-variable 'stringp)
 
@@ -378,7 +379,10 @@
                 ;; In case comment-start has changed since last time.
                 (string-match comment-start-skip comment-start))
       (set (make-local-variable 'comment-start-skip)
-          (concat "\\(\\(^\\|[^\\\n]\\)\\(\\\\\\\\\\)*\\)\\(\\s<+\\|"
+          (concat (unless (eq comment-use-syntax t)
+                     ;; `syntax-ppss' will detect escaping.
+                     "\\(\\(^\\|[^\\\n]\\)\\(\\\\\\\\\\)*\\)")
+                   "\\(\\s<+\\|"
                   (regexp-quote (comment-string-strip comment-start t t))
                   ;; Let's not allow any \s- but only [ \t] since \n
                   ;; might be both a comment-end marker and \s-.
@@ -523,12 +527,11 @@
         (when (nth 4 state)
           (goto-char (nth 8 state))
           (prog1 (point)
-            (when (or (looking-at comment-start-skip)
-                      ;; Some older modes use regexps that check the
-                      ;; char before the comment for quoting.  (Bug#16971)
-                      (save-excursion
-                        (forward-char -1)
-                        (looking-at comment-start-skip)))
+            (when (save-restriction
+                    ;; `comment-start-skip' sometimes checks that the
+                    ;; comment char is not escaped.  (Bug#16971)
+                    (narrow-to-region (point) (point-max))
+                    (looking-at comment-start-skip))
               (goto-char (match-end 0))))))
     ;; Can't rely on the syntax table, let's guess based on font-lock.
     (unless (eq (get-text-property (point) 'face) 'font-lock-string-face)