Improve inline link highlighting

Author: syohex

CHANGES.md

@@ -16,6 +16,7 @@
     - Angle URL fontify issue which was introduced by [GH-861][] [GH-895][]
     - Fix list item bound calculation when tab indentation is used [GH-904][]
     - Fix `markdown-heading-at-point` at the end of line [GH-912][]
+    - Catch an exception when `scan-sexp` fails [GH-917][]
 
 *   Improvements:
     - Support drag and drop features on Windows and multiple files' drag and drop
@@ -32,6 +33,7 @@
   [gh-904]: https://github.com/jrblevin/markdown-mode/issues/904
   [gh-910]: https://github.com/jrblevin/markdown-mode/issues/910
   [gh-912]: https://github.com/jrblevin/markdown-mode/issues/912
+  [gh-917]: https://github.com/jrblevin/markdown-mode/issues/917
 
 # Markdown Mode 2.7
 

markdown-mode.el

@@ -3282,11 +3282,18 @@ processed elements."
                              (markdown-end-of-text-block)
                              (point))))
            ;; Move over balanced expressions to closing right bracket.
-           ;; Catch unbalanced expression errors and return nil.
+           ;; Catch unbalanced expression errors, then try to search right bracket manually.
            (first-end (condition-case nil
                           (and (goto-char first-begin)
                                (scan-sexps (point) 1))
-                        (error nil)))
+                        (error
+                         (save-match-data
+                           (let ((last (match-end 4))
+                                 ok end-pos)
+                             (while (and (not ok) (search-forward "]" last t))
+                               (unless (= (char-before (1- (point))) ?\\)
+                                 (setq ok t end-pos (point))))
+                             end-pos)))))
            ;; Continue with point at CONT-POINT upon failure.
            (cont-point (min (1+ first-begin) last))
            second-begin second-end url-begin url-end
@@ -8183,7 +8190,9 @@ Value is a list of elements describing the link:
               url (match-string-no-properties 6))
         ;; consider nested parentheses
         ;; if link target contains parentheses, (match-end 0) isn't correct end position of the link
-        (let* ((close-pos (scan-sexps (match-beginning 5) 1))
+        (let* ((close-pos (condition-case nil
+                              (scan-sexps (match-beginning 5) 1)
+                            (error (match-end 0))))
                (destination-part (string-trim (buffer-substring-no-properties (1+ (match-beginning 5)) (1- close-pos)))))
           (setq end close-pos)
           ;; A link can contain spaces if it is wrapped with angle brackets

tests/markdown-test.el

@@ -3188,7 +3188,15 @@ Detail: https://github.com/jrblevin/markdown-mode/issues/409"
     (markdown-test-range-has-face 2 24 'markdown-link-face)
     (markdown-test-range-has-face 25 26 'markdown-markup-face)
     (markdown-test-range-has-face 27 40 'markdown-url-face)
-    (markdown-test-range-has-face 41 41 'markdown-markup-face)))
+    (markdown-test-range-has-face 41 41 'markdown-markup-face))
+
+  ;; https://github.com/jrblevin/markdown-mode/issues/917
+  (markdown-test-string "[(foo](http://foo.com)"
+    (markdown-test-range-has-face 1 1 'markdown-markup-face)
+    (markdown-test-range-has-face 2 5 'markdown-link-face)
+    (markdown-test-range-has-face 6 7 'markdown-markup-face)
+    (markdown-test-range-has-face 8 21 'markdown-url-face)
+    (markdown-test-range-has-face 22 22 'markdown-markup-face)))
 
 (ert-deftest test-markdown-font-lock/pre-comment ()
   "Test comments inside of a pre block."