* lisp/paren.el (show-paren-function): Don't show escaped parens.

Let-bind `unescaped' to `t' when paren is not escaped.

Fixes: debbugs:9461

2 files changed, 20 insertions, 5 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d1a219dfb8d..311c02e64b3 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2011-09-10  Juri Linkov  <juri@jurta.org>
+
+        * paren.el (show-paren-function): Don't show escaped parens.
+        Let-bind `unescaped' to `t' when paren is not escaped.  (Bug#9461)
+
 2011-09-10  Eli Zaretskii  <eliz@gnu.org>
 
         * mail/sendmail.el (mml-to-mime, mml-attach-file)
diff --git a/lisp/paren.el b/lisp/paren.el
index 8bd96b9317a..fb5c0bf36e9 100644
--- a/lisp/paren.el
+++ b/lisp/paren.el
@@ -135,13 +135,23 @@ in `show-paren-style' after `show-paren-delay' seconds of Emacs idle time."
 ;; and show it until input arrives.
 (defun show-paren-function ()
   (if show-paren-mode
-      (let ((oldpos (point))
-            (dir (cond ((eq (syntax-class (syntax-after (1- (point)))) 5) -1)
-                       ((eq (syntax-class (syntax-after (point)))      4) 1)))
-            pos mismatch face)
+      (let* ((oldpos (point))
+             (dir (cond ((eq (syntax-class (syntax-after (1- (point)))) 5) -1)
+                        ((eq (syntax-class (syntax-after (point)))      4) 1)))
+             (unescaped
+              (when dir
+                ;; Verify an even number of quoting characters precede the paren.
+                ;; Follow the same logic as in `blink-matching-open'.
+                (= (if (= dir -1) 1 0)
+                   (logand 1 (- (point)
+                                (save-excursion
+                                  (if (= dir -1) (forward-char -1))
+                                  (skip-syntax-backward "/\\")
+                                  (point)))))))
+             pos mismatch face)
         ;;
         ;; Find the other end of the sexp.
-        (when dir
+        (when unescaped
           (save-excursion
             (save-restriction
               ;; Determine the range within which to look for a match.