From: Alan Mackenzie <acm@muc.de>
Date: Sun, 16 Feb 2020 17:46:02 +0000 (+0000)
Subject: Amend c-backward-sws better to handle multiline block comments
X-Git-Tag: emacs-27.0.90~45
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=efc9d4fe3ef256e6c546c1690bf7dd968f1fdac8;p=emacs.git

Amend c-backward-sws better to handle multiline block comments

In particular, multiline comments lacking escaped newlines.

* lisp/progmodes/cc-engine.el (c-backward-sws): Whilst searching backward for
a putative beginning of macro, move back over block comments whose innards
lack escaped newlines.
---

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 0964c04b899..0c338fa3868 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -327,6 +327,8 @@ comment at the start of cc-engine.el for more info."
 	  (when (or (null lim)
 		    (>= here lim))
 	    (save-match-data
+	      ;; Note the similarity of the code here to some in
+	      ;; `c-backward-sws'.
 	      (while
 		  (progn
 		    (while (eq (char-before (1- (point))) ?\\)
@@ -2461,17 +2463,34 @@ comment at the start of cc-engine.el for more info."
 		   (/= cmt-skip-pos simple-ws-beg)
 		   (c-beginning-of-macro))
 	      ;; Inside a cpp directive.  See if it should be skipped over.
-	      (let ((cpp-beg (point)))
+	      (let ((cpp-beg (point))
+		    pause pos)
 
-		;; Move back over all line continuations in the region skipped
-		;; over by `c-backward-comments'.  If we go past it then we
-		;; started inside the cpp directive.
+		;; Move back over all line continuations and block comments in
+		;; the region skipped over by `c-backward-comments'.  If we go
+		;; past it then we started inside the cpp directive.
 		(goto-char simple-ws-beg)
 		(beginning-of-line)
-		(while (and (> (point) cmt-skip-pos)
-			    (progn (backward-char)
-				   (eq (char-before) ?\\)))
-		  (beginning-of-line))
+		;; Note the similarity of the code here to some in
+		;; `c-beginning-of-macro'.
+		(setq pause (point))
+		(while
+		    (progn
+		      (while (and (> (point) cmt-skip-pos)
+				  (progn (backward-char)
+					 (eq (char-before) ?\\)))
+			(beginning-of-line))
+		      (setq pos (point))
+		      (when (and c-last-c-comment-end-on-line-re
+				 (re-search-forward
+				  c-last-c-comment-end-on-line-re pause t))
+			(goto-char (match-end 1))
+			(if (c-backward-single-comment)
+			    (progn
+			      (beginning-of-line)
+			      (setq pause (point)))
+			  (goto-char pos)
+			  nil))))
 
 		(if (< (point) cmt-skip-pos)
 		    ;; Don't move past the cpp directive if we began inside