2 files changed, 35 insertions, 2 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index a25d0595535..ed8310d0e67 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -1253,12 +1253,20 @@ comment at the start of cc-engine.el for more info."
                   ;; (including a case label) or something like C++'s "public:"?
                   ;; A case label might use an expression rather than a token.
                   (setq after-case:-pos (or tok start))
-                  (if (or (looking-at c-nonlabel-token-key) ; e.g. "while" or "'a'"
+                  (if (or (looking-at c-nonlabel-nonparen-token-key)
+                                        ; e.g. "while" or "'a'"
                           ;; Catch C++'s inheritance construct "class foo : bar".
                           (save-excursion
                             (and
                              (c-safe (c-backward-sexp) t)
-                             (looking-at c-nonlabel-token-2-key))))
+                             (looking-at c-nonlabel-token-2-key)))
+                          ;; Catch C++'s "case a(1):"
+                          (and (c-major-mode-is 'c++-mode)
+                               (eq (char-after) ?\()
+                               (save-excursion
+                                 (not (and
+                                       (zerop (c-backward-token-2 2))
+                                       (looking-at c-case-kwds-regexp))))))
                       (setq c-maybe-labelp nil)
                     (if after-labels-pos ; Have we already encountered a label?
                         (if (not last-label-pos)
diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 8b7e4ef7c09..30da10a6c03 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -3674,6 +3674,31 @@ i.e. before \":\".  Only used if `c-recognize-colon-labels' is set."
   c++ (concat "\\s(\\|\"\\|" (c-lang-const c-nonlabel-token-key)))
 (c-lang-defvar c-nonlabel-token-key (c-lang-const c-nonlabel-token-key))
 
+(c-lang-defconst c-nonlabel-nonparen-token-key
+  "Regexp matching things that can't occur in generic colon labels,
+neither in a statement nor in a declaration context, with the
+exception of an open parenthesis.  The regexp is tested at the
+beginning of every sexp in a suspected label, i.e. before \":\".
+Only used if `c-recognize-colon-labels' is set."
+  ;; This lang const is the same as `c-nonlabel-token-key', except for a
+  ;; slight difference in the c++-mode value.
+  t (concat
+     ;; All keywords except `c-label-kwds' and `c-protection-kwds'.
+     (c-make-keywords-re t
+       (c--set-difference (c-lang-const c-keywords)
+                          (append (c-lang-const c-label-kwds)
+                                  (c-lang-const c-protection-kwds))
+                          :test 'string-equal)))
+  ;; Don't allow string literals, except in AWK and Java.  Character constants are OK.
+  (c objc pike idl) (concat "\"\\|"
+                            (c-lang-const c-nonlabel-nonparen-token-key))
+  ;; Also check for open parens in C++, to catch member init lists in
+  ;; constructors.  We normally allow it so that macros with arguments
+  ;; work in labels.
+  c++ (concat "[{[]\\|\"\\|" (c-lang-const c-nonlabel-nonparen-token-key)))
+(c-lang-defvar c-nonlabel-nonparen-token-key
+  (c-lang-const c-nonlabel-nonparen-token-key))
+
 (c-lang-defconst c-nonlabel-token-2-key
   "Regexp matching things that can't occur two symbols before a colon in
 a label construct.  This catches C++'s inheritance construct \"class foo