bug#63285: 30.0.50; CC Mode: K&R argument declaration misdetection after parenthesized type

[Olivier Certner <ocert.dev@free.fr>]

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Sorry, I had clobbered the "(+ (point) 1000)" part in the previous patch.

Please use this one instead.

-- 
Olivier Certner

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From 0515de23d84a48c57b456c6730f826c5d783b965 Mon Sep 17 00:00:00 2001
From: Olivier Certner <olce.emacs@certner.fr>
Date: Wed, 3 May 2023 11:44:43 +0200
Subject: [PATCH] CC Mode: Fix K&R argument declaration misdetection after
 parenthesized type

* lisp/progmodes/cc-engine.el (c-in-knr-argdecl): When trying to loop
over candidate declarations (between the function declaration's
identifier list's end and point) to check whether the names of their
identifiers correspond with that of the identifier list, actually fail
as soon as stumbling on something other than a declaration instead of
silently succeeding, which causes some constructs to be erroneously
recognized as K&R argument declarations.

(Bug#63285)
---
 lisp/progmodes/cc-engine.el | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 8b34daf03c2..27740b4903c 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -12039,17 +12039,24 @@ c-in-knr-argdecl
 		       ;; Each time around the following checks one
 		       ;; declaration (which may contain several identifiers).
 		       (while (and
-			       (consp (setq decl-or-cast
-					    (c-forward-decl-or-cast-1
-					     after-prec-token
-					     nil ; Or 'arglist ???
-					     nil)))
-			       (memq (char-after) '(?\; ?\,))
-			       (goto-char (car decl-or-cast))
-			       (save-excursion
-				 (setq semi-position+1
-				       (c-syntactic-re-search-forward
-					";" (+ (point) 1000) t)))
+			       (or
+				(and
+				 (consp (setq decl-or-cast
+					      (c-forward-decl-or-cast-1
+					       after-prec-token
+					       nil ; Or 'arglist ???
+					       nil)))
+				 (memq (char-after) '(?\; ?\,))
+				 (goto-char (car decl-or-cast))
+				 (save-excursion
+				   (setq semi-position+1
+					 (1+ (or
+					      (c-syntactic-re-search-forward
+					       ";" (+ (point) 1000) t)
+					      (1- (point-max)))))))
+				;; Can't parse declarations correctly,
+				;; bail out.
+				(throw 'knr nil))
 			       (c-do-declarators
 				semi-position+1 t nil nil
 				(lambda (id-start id-end _next _not-top
-- 
2.39.2