(c-mask-comment): A better way to ensure point doesn't move around

unexpectedly.  Also handles the paragraph fill case.

diff --git a/lisp/progmodes/cc-cmds.el b/lisp/progmodes/cc-cmds.el
index 96b72eb17544b6b995ea2eca97c04f54da866cb7..b23b76579967dd42f7db8adc2e13c38ba19d1822 100644 (file)
--- a/lisp/progmodes/cc-cmds.el
+++ b/lisp/progmodes/cc-cmds.el
@@ -2761,10 +2761,14 @@ command to conveniently insert and align the necessary backslashes."
                  '("" . 0))))))
     ))
 
-(defun c-mask-comment (fill-mode apply-outside-literal fun &rest args)
+(defun c-mask-comment (fill-paragraph apply-outside-literal fun &rest args)
   ;; Calls FUN with ARGS ar arguments.  If point is inside a comment,
   ;; the comment starter and ender are masked and the buffer is
   ;; narrowed to make it look like a normal paragraph during the call.
+  ;;
+  ;; FILL-PARAGRAPH is non-nil if called for paragraph filling.  The
+  ;; position of point is then less significant when doing masking and
+  ;; narrowing.
   (let (fill
        ;; beg and end limits the region to narrow.  end is a marker.
        beg end
@@ -2790,7 +2794,7 @@ command to conveniently insert and align the necessary backslashes."
       ;; Widen to catch comment limits correctly.
       (widen)
       (unless c-lit-limits
-       (setq c-lit-limits (c-literal-limits nil fill-mode)))
+       (setq c-lit-limits (c-literal-limits nil fill-paragraph)))
       (setq c-lit-limits (c-collect-line-comments c-lit-limits))
       (unless c-lit-type
        (setq c-lit-type (c-literal-type c-lit-limits))))
@@ -2840,8 +2844,8 @@ command to conveniently insert and align the necessary backslashes."
                                                 "\\)\\*/"))
                             (eq (cdr c-lit-limits) (match-end 0))
                             ;; Leave the comment ender on its own line.
-                            (set-marker end (max (point) here))))
-               (when fill-mode
+                            (set-marker end (point))))
+               (when fill-paragraph
                  ;; The comment ender should hang.  Replace all cruft
                  ;; between it and the last word with one or two 'x'
                  ;; and include it in the region.  We'll change them
@@ -2900,13 +2904,11 @@ command to conveniently insert and align the necessary backslashes."
              ;; The region includes the comment starter.
              (save-excursion
                (goto-char (car c-lit-limits))
-               (when (and (looking-at comment-start-skip)
-                          (> here (match-end 0)))
-                 (if (eq (match-end 0) (c-point 'eol))
-                     ;; Begin with the next line.
-                     (setq beg (c-point 'bonl))
-                   ;; Fake the fill prefix in the first line.
-                   (setq tmp-pre t))))))
+               (if (looking-at (concat "\\(" comment-start-skip "\\)$"))
+                   ;; Begin with the next line.
+                   (setq beg (c-point 'bonl))
+                 ;; Fake the fill prefix in the first line.
+                 (setq tmp-pre t)))))
           ((eq c-lit-type 'string)     ; String.
            (save-excursion
              (when (>= end (cdr c-lit-limits))
@@ -2984,24 +2986,24 @@ Warning: Regexp from `c-comment-prefix-regexp' doesn't match the comment prefix
                                              ""))))
                           (car (or fill (c-guess-fill-prefix
                                          c-lit-limits c-lit-type))))))
-                   ;; Don't remember why I added this, but it doesn't
-                   ;; work correctly since `here' can point anywhere
-                   ;; after the deletes and inserts above.
-                   ;(point-rel (cond ((< here beg) (- here beg))
-                   ;                  ((> here end) (- here end))))
-                   )
+                   ;; Save the relative position of point if it's
+                   ;; outside the region we're going to narrow.  Want
+                   ;; to restore it in that case, but otherwise it
+                   ;; should be moved according to the called
+                   ;; function.
+                   (point-rel (cond ((< (point) beg) (- (point) beg))
+                                    ((> (point) end) (- (point) end)))))
                ;; Preparations finally done! Now we can call the
                ;; actual function.
                (prog1
                    (save-restriction
                      (narrow-to-region beg end)
                      (apply fun args))
-                 ;(if point-rel
-                 ;    ;; Restore point if it was outside the region.
-                 ;    (if (< point-rel 0)
-                 ;       (goto-char (+ beg point-rel))
-                 ;     (goto-char (+ end point-rel))))
-                 ))
+                 (if point-rel
+                     ;; Restore point if it was outside the region.
+                     (if (< point-rel 0)
+                         (goto-char (+ beg point-rel))
+                       (goto-char (+ end point-rel))))))
            (when apply-outside-literal
              (apply fun args))))
       (when (consp tmp-pre)