From e05dd60c123cdc7224623fd68f18c75b486a6783 Mon Sep 17 00:00:00 2001
From: Steve Purcell <steve@sanityinc.com>
Date: Mon, 29 Sep 2014 14:17:16 +0100
Subject: [PATCH] Don't propertize if the syntax table is unset

`rainbow-delimiters-mode' may be restored via desktop.el. When this
happens inside an `mmm-mode' buffer, the subregion-specific values of
the syntax table will not be restored, and so
`rainbow-delimiters-syntax-table' can be nil. We handle this case by
skipping propertization if the syntax table is unset.

Closes https://github.com/purcell/emacs.d/issues/209
---
 rainbow-delimiters.el | 67 ++++++++++++++++++++++---------------------
 1 file changed, 34 insertions(+), 33 deletions(-)

diff --git a/rainbow-delimiters.el b/rainbow-delimiters.el
index cf9b7fe..6d9ed3b 100644
--- a/rainbow-delimiters.el
+++ b/rainbow-delimiters.el
@@ -490,41 +490,42 @@ TYPE is the delimiter type string for `rainbow-delimiters-apply-color'.")
 Used by font-lock for dynamic highlighting."
   (setq rainbow-delimiters-escaped-char-predicate
         (cdr (assoc major-mode rainbow-delimiters-escaped-char-predicate-list)))
-  (with-syntax-table rainbow-delimiters-syntax-table
-    (let ((inhibit-point-motion-hooks t))
-      ;; Point can be anywhere in buffer; determine the nesting depth at point.
-      (let* ((last-ppss-pos (point))
-             (ppss (rainbow-delimiters-syntax-ppss last-ppss-pos))
-             (depth (rainbow-delimiters-depth ppss)))
-        (while (and (< (point) end)
-                    (re-search-forward rainbow-delimiters-delim-regex end t))
-          (let ((delim-pos (match-beginning 0)))
-            (setq ppss (save-excursion
-                         (parse-partial-sexp last-ppss-pos delim-pos nil nil ppss)))
-            (setq last-ppss-pos delim-pos)
-            (unless (rainbow-delimiters-char-ineligible-p delim-pos ppss)
-              (let* ((delim (char-after delim-pos))
-                     (opening-delim-info
-                      (assq delim rainbow-delimiters-opening-delim-info)))
-                (if opening-delim-info
-                    (progn
-                      (setq depth (1+ depth))
-                      (rainbow-delimiters-apply-color (cdr opening-delim-info)
+  (when rainbow-delimiters-syntax-table
+    (with-syntax-table rainbow-delimiters-syntax-table
+      (let ((inhibit-point-motion-hooks t))
+        ;; Point can be anywhere in buffer; determine the nesting depth at point.
+        (let* ((last-ppss-pos (point))
+               (ppss (rainbow-delimiters-syntax-ppss last-ppss-pos))
+               (depth (rainbow-delimiters-depth ppss)))
+          (while (and (< (point) end)
+                      (re-search-forward rainbow-delimiters-delim-regex end t))
+            (let ((delim-pos (match-beginning 0)))
+              (setq ppss (save-excursion
+                           (parse-partial-sexp last-ppss-pos delim-pos nil nil ppss)))
+              (setq last-ppss-pos delim-pos)
+              (unless (rainbow-delimiters-char-ineligible-p delim-pos ppss)
+                (let* ((delim (char-after delim-pos))
+                       (opening-delim-info
+                        (assq delim rainbow-delimiters-opening-delim-info)))
+                  (if opening-delim-info
+                      (progn
+                        (setq depth (1+ depth))
+                        (rainbow-delimiters-apply-color (cdr opening-delim-info)
+                                                        depth
+                                                        delim-pos
+                                                        t))
+                    ;; Not an opening delimiter, so it's a closing delimiter.
+                    (let ((closing-delim-info
+                           (assq delim rainbow-delimiters-closing-delim-info))
+                          (matching-opening-delim (char-after (nth 1 ppss))))
+                      (rainbow-delimiters-apply-color (nthcdr 2 closing-delim-info)
                                                       depth
                                                       delim-pos
-                                                      t))
-                  ;; Not an opening delimiter, so it's a closing delimiter.
-                  (let ((closing-delim-info
-                         (assq delim rainbow-delimiters-closing-delim-info))
-                        (matching-opening-delim (char-after (nth 1 ppss))))
-                    (rainbow-delimiters-apply-color (nthcdr 2 closing-delim-info)
-                                                    depth
-                                                    delim-pos
-                                                    (= (nth 1 closing-delim-info)
-                                                       matching-opening-delim))
-                    (setq depth (if (<= depth 0)
-                                    0   ; unmatched delim
-                                  (1- depth))))))))))))
+                                                      (= (nth 1 closing-delim-info)
+                                                         matching-opening-delim))
+                      (setq depth (if (<= depth 0)
+                                      0 ; unmatched delim
+                                    (1- depth)))))))))))))
   ;; We already fontified the delimiters, tell font-lock there's nothing more
   ;; to do.
   nil)