emacs-27 884b68c: CC Mode: Fontify foo in "const auto foo :" correctly

[Alan Mackenzie]

branch: emacs-27
commit 884b68ca2c63c98d3fa90ca5f11b47286d2fb85c
Author: Alan Mackenzie <address@hidden>
Commit: Alan Mackenzie <address@hidden>

    CC Mode: Fontify foo in "const auto foo :" correctly
    
    * lisp/progmodes/cc-engine.el (c-forward-decl-or-cast-1): While attempting 
to
    find a declaration's identifier, recast the latest found id. as that
    identifier when there is no other type identifier and the result of the most
    recent c-forward-type call is 'maybe or 'found.  In the latter case, remove
    the id. from the found types list, too.
---
 lisp/progmodes/cc-engine.el | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 0c338fa..447942e 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -9275,9 +9275,10 @@ This function might do hidden buffer changes."
   ;;
   ;;   The third element of the return value is non-nil when the declaration
   ;;   parsed might be an expression.  The fourth element is the position of
-  ;;   the start of the type identifier.  The fifth element is t if either
-  ;;   CONTEXT was 'top, or the declaration is detected to be treated as top
-  ;;   level (e.g. with the keyword "extern").
+  ;;   the start of the type identifier, or the same as the first element when
+  ;;   there is no type identifier.  The fifth element is t if either CONTEXT
+  ;;   was 'top, or the declaration is detected to be treated as top level
+  ;;   (e.g. with the keyword "extern").
   ;;
   ;; If a cast is parsed:
   ;;
@@ -9680,7 +9681,26 @@ This function might do hidden buffer changes."
               (setq got-identifier (c-forward-name))
               (setq name-start pos))
          (when (looking-at "[0-9]")
-           (setq got-number t))) ; We've probably got an arithmetic expression.
+           (setq got-number t)) ; We probably have an arithmetic expression.
+         (and maybe-typeless
+              (or (eq at-type 'maybe)
+                  (when (eq at-type 'found)
+                    ;; Remove the ostensible type from the found types list.
+                    (when type-start
+                      (c-unfind-type
+                       (buffer-substring-no-properties
+                        type-start
+                        (save-excursion
+                          (goto-char type-start)
+                          (c-end-of-token)
+                          (point)))))
+                    t))
+              ;; The token which we assumed to be a type is actually the
+              ;; identifier, and we have no explicit type.
+              (setq at-type nil
+                    name-start type-start
+                    id-start type-start
+                    got-identifier t)))
 
       ;; Skip over type decl suffix operators and trailing noise macros.
       (while