Make c-defun-name analyze more thoroughly a function type which is a struct

This fixes bug #29293.

* lisp/progmodes/cc-cmds.el (c-defun-name): When a struct (etc.) type is
encountered, check whether it is the return type of a function rather than a
declaration of the struct itself.  Similarly adapt the cond arm which deals
with functions properly to recognize struct return types.

1 files changed, 19 insertions, 3 deletions

diff --git a/lisp/progmodes/cc-cmds.el b/lisp/progmodes/cc-cmds.el
index 2b663135932..471560e19d4 100644
--- a/lisp/progmodes/cc-cmds.el
+++ b/lisp/progmodes/cc-cmds.el
@@ -1849,7 +1849,15 @@ with a brace block."
           ;; Pick out the defun name, according to the type of defun.
           (cond
            ;; struct, union, enum, or similar:
-           ((looking-at c-type-prefix-key)
+           ((save-excursion
+              (and
+               (looking-at c-type-prefix-key)
+               (consp (c-forward-decl-or-cast-1 (c-point 'bosws) 'top nil))
+               (or (not (or (eq (char-after) ?{)
+                            (and c-recognize-knr-p
+                                 (c-in-knr-argdecl))))
+                   (progn (c-backward-syntactic-ws)
+                          (not (eq (char-before) ?\)))))))
             (let ((key-pos (point)))
               (c-forward-over-token-and-ws) ; over "struct ".
               (cond
@@ -1897,8 +1905,16 @@ with a brace block."
 
            (t
             ;; Normal function or initializer.
-            (when (c-syntactic-re-search-forward "[{(]" nil t)
-              (backward-char)
+            (when
+                (and
+                 (consp (c-forward-decl-or-cast-1 (c-point 'bosws) 'top nil))
+                 (or (eq (char-after) ?{)
+                     (and c-recognize-knr-p
+                          (c-in-knr-argdecl)))
+                 (progn
+                   (c-backward-syntactic-ws)
+                   (eq (char-before) ?\)))
+                 (c-go-list-backward))
               (c-backward-syntactic-ws)
               (when (eq (char-before) ?\=) ; struct foo bar = {0, 0} ;
                 (c-backward-token-2)