Fix a "wrong side of point" error in CC Mode. Fixes bug #28850.

The cause was a scanning over a bracket pair taking us beyond the supplied
LIMIT parameter in c-forward-declarator.

* lisp/progmodes/cc-engine.el (c-forward-declarator): Add three checks (<
(point) limit) whilst dealing with tokens after the declared identifier.

* lisp/progmodes/cc-fonts.el (c-font-lock-declarators): Don't supply a LIMIT
argument to `c-forward-declarator' (twice), since we want to fontify up till
the end of a declarator, not an arbitrary jit-lock chunk end.

2 files changed, 6 insertions, 4 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index c506294c5a0..457f95f2ca3 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -8112,12 +8112,14 @@ comment at the start of cc-engine.el for more info."
          ;; initializing brace lists.
          (let (found)
            (while
-               (and (progn
+               (and (< (point) limit)
+                    (progn
                       ;; In the next loop, we keep searching forward whilst
                       ;; we find ":"s which aren't single colons inside C++
                       ;; "for" statements.
                       (while
                           (and
+                           (< (point) limit)
                            (setq found
                                  (c-syntactic-re-search-forward
                                   "[;:,]\\|\\s)\\|\\(=\\|\\s(\\)"
@@ -8139,7 +8141,7 @@ comment at the start of cc-engine.el for more info."
                     (c-go-up-list-forward))
              (setq brackets-after-id t))
            (when found (backward-char))
-           t))
+           (<= (point) limit)))
         (list id-start id-end brackets-after-id (match-beginning 1) decorated)
 
       (goto-char here)
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index acdb1ad1334..a2ac2a32535 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1062,7 +1062,7 @@ casts and declarations are fontified.  Used on level 2 and higher."
     ;; The following `while' fontifies a single declarator id each time round.
     ;; It loops only when LIST is non-nil.
     (while
-        (and pos (setq decl-res (c-forward-declarator limit)))
+        (and pos (setq decl-res (c-forward-declarator)))
       (setq next-pos (point)
             id-start (car decl-res)
             id-face (if (and (eq (char-after) ?\()
@@ -1091,7 +1091,7 @@ casts and declarations are fontified.  Used on level 2 and higher."
                                                (throw 'is-function nil))
                                               ((not (eq got-type 'maybe))
                                                (throw 'is-function t)))
-                                             (c-forward-declarator limit t)
+                                             (c-forward-declarator nil t)
                                              (eq (char-after) ?,))
                                          (forward-char)
                                          (c-forward-syntactic-ws))