Fix loss of documentation face in certain CC Mode doc comment situations

* lisp/progmodes/cc-fonts.el (c-font-lock-doc-comments): Take into account
the possibility of font-lock-comment-delimiter-face.  Test rigorously for
"/**" (etc.) being itself inside a literal, rather than just depending on the
face of the previous character.

1 files changed, 10 insertions, 3 deletions

diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 7b99c2f54e5..83038e07ca6 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -2670,8 +2670,8 @@ need for `pike-font-lock-extra-types'.")
   ;; This function might do hidden buffer changes.
 
   (let (comment-beg region-beg)
-    (if (eq (get-text-property (point) 'face)
-            'font-lock-comment-face)
+    (if (memq (get-text-property (point) 'face)
+              '(font-lock-comment-face font-lock-comment-delimiter-face))
         ;; Handle the case when the fontified region starts inside a
         ;; comment.
         (let ((start (c-literal-start)))
@@ -2691,8 +2691,15 @@ need for `pike-font-lock-extra-types'.")
                      (or (not (c-got-face-at comment-beg
                                              c-literal-faces))
                          (and (/= comment-beg (point-min))
+                              ;; Cheap check which is unreliable (the previous
+                              ;; character could be the end of a previous
+                              ;; comment).
                               (c-got-face-at (1- comment-beg)
-                                             c-literal-faces))))
+                                             c-literal-faces)
+                              ;; Expensive reliable check.
+                              (save-excursion
+                                (goto-char comment-beg)
+                                (c-in-literal)))))
               (setq comment-beg nil))
             (setq region-beg comment-beg))