>From 05d10742e01cc3dceb4f465695daee7cc42215d6 Mon Sep 17 00:00:00 2001
From: Dmitry Gutov <dgutov@yandex.ru>
Date: Wed, 25 Apr 2012 06:55:50 +0400
Subject: [PATCH] ruby-mode: Don't propertize percent literals inside strings

---
 lisp/progmodes/ruby-mode.el |   58 ++++++++++++++++++++++++-------------------
 test/indent/ruby.rb         |    3 +++
 2 files changed, 35 insertions(+), 26 deletions(-)

diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 5d79437..9ed3879 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -1162,7 +1162,7 @@ See `add-log-current-defun-function'."
            (7 (prog1 "\"" (ruby-syntax-propertize-heredoc end))))
           ;; Handle percent literals: %w(), %q{}, etc.
           ("\\(?:^\\|[[ \t\n<+(,=]\\)\\(%\\)[qQrswWx]?\\([[:punct:]]\\)"
-           (1 (prog1 "|" (ruby-syntax-propertize-general-delimiters end)))))
+           (1 (ruby-syntax-propertize-general-delimiters end))))
          (point) end))
 
       (defun ruby-syntax-propertize-heredoc (limit)
@@ -1198,31 +1198,37 @@ See `add-log-current-defun-function'."
             (beginning-of-line))))
 
       (defun ruby-syntax-propertize-general-delimiters (limit)
-        (goto-char (match-beginning 2))
-        (let* ((op (char-after))
-               (ops (char-to-string op))
-               (cl (or (cdr (aref (syntax-table) op))
-                       (cdr (assoc op '((?< . ?>))))))
-               parse-sexp-lookup-properties)
-          (ignore-errors
-            (if cl
-                (progn  ; Paired delimiters.
-                  ;; Delimiter pairs of the same kind can be nested
-                  ;; inside the literal, as long as they are balanced.
-                  ;; Create syntax table that ignores other characters.
-                  (with-syntax-table (make-char-table 'syntax-table nil)
-                    (modify-syntax-entry op (concat "(" (char-to-string cl)))
-                    (modify-syntax-entry cl (concat ")" ops))
-                    (modify-syntax-entry ?\\ "\\")
-                    (save-restriction
-                      (narrow-to-region (point) limit)
-                      (forward-list))))  ; skip to the paired character
-              ;; Single character delimiter.
-              (re-search-forward (concat "[^\\]\\(?:\\\\\\\\\\)*"
-                                         (regexp-quote ops)) limit nil))
-            ;; If we reached here, the closing delimiter was found.
-            (put-text-property (1- (point)) (point)
-                               'syntax-table (string-to-syntax "|")))))
+        (goto-char (match-beginning 1)) ; When multiline, the beginning
+        (let ((state (syntax-ppss))     ; may already be propertized.
+              (syntax-value (string-to-syntax "|")))
+          ;; Move forward either way, to escape inf loop.
+          (goto-char (match-beginning 2))
+          (unless (nth 3 state) ; not inside a string
+            (let* ((op (char-after))
+                   (ops (char-to-string op))
+                   (cl (or (cdr (aref (syntax-table) op))
+                           (cdr (assoc op '((?< . ?>))))))
+                   parse-sexp-lookup-properties)
+              (ignore-errors
+                (if cl
+                    (progn ; Paired delimiters.
+                      ;; Delimiter pairs of the same kind can be nested
+                      ;; inside the literal, as long as they are balanced.
+                      ;; Create syntax table that ignores other characters.
+                      (with-syntax-table (make-char-table 'syntax-table nil)
+                        (modify-syntax-entry op (concat "(" (char-to-string cl)))
+                        (modify-syntax-entry cl (concat ")" ops))
+                        (modify-syntax-entry ?\\ "\\")
+                        (save-restriction
+                          (narrow-to-region (point) limit)
+                          (forward-list)))) ; skip to the paired character
+                  ;; Single character delimiter.
+                  (re-search-forward (concat "[^\\]\\(?:\\\\\\\\\\)*"
+                                             (regexp-quote ops)) limit nil))
+                ;; If we reached here, the closing delimiter was found.
+                (put-text-property (1- (point)) (point) 'syntax-table
+                                   syntax-value)))
+            syntax-value)))
       )
 
   ;; For Emacsen where syntax-propertize-rules is not (yet) available,
diff --git a/test/indent/ruby.rb b/test/indent/ruby.rb
index c4a747a..fe1986a 100644
--- a/test/indent/ruby.rb
+++ b/test/indent/ruby.rb
@@ -7,6 +7,9 @@ c = %w(foo
  baz)
 d = %!hello!
 
+# Don't propertize percent literals inside strings.
+"(%s, %s)" % [123, 456]
+
 # A "do" after a slash means that slash is not a division, but it doesn't imply
 # it's a regexp-ender, since it can be a regexp-starter instead!
 x = toto / foo; if /do bar/ then
-- 
1.7.10.msysgit.1