Fix misfontification of C++ member initialization list after "throw"

* lisp/progmodes/cc-engine.el (c-forward-type): Stop recognizing a "type"
starting with "throw", by using c-opt-type-modifier-prefix-key.

* lisp/progmodes/cc-langs.el (c-type-modifier-prefix-kwds): New lang const
which, in C++, doesn't contain "throw", otherwise like c-type-modifier-kwds.
(c-opt-type-modifier-prefix-key): New lang const and var, a regexp matching
any keyword in the previous lang const.

1 files changed, 22 insertions, 6 deletions

diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 869048bee31..169b61c3dd3 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -1925,16 +1925,32 @@ on one of the `*-decl-kwds' lists."
   t (c-make-keywords-re t (c-lang-const c-type-prefix-kwds)))
 (c-lang-defvar c-type-prefix-key (c-lang-const c-type-prefix-key))
 
-(c-lang-defconst c-type-modifier-kwds
-  "Type modifier keywords.  These can occur almost anywhere in types
-but they don't build a type of themselves.  Unlike the keywords on
-`c-primitive-type-kwds', they are fontified with the keyword face and
-not the type face."
+(c-lang-defconst c-type-modifier-prefix-kwds
+  "Type modifier keywords which can appear in front of a type.  These can
+also occur almost anywhere in types but they don't build a type of
+themselves.  Unlike the keywords on `c-primitive-type-kwds', they are
+fontified with the keyword face and not the type face."
   t    nil
   c    '("const" "restrict" "volatile")
-  c++  '("const" "noexcept" "volatile" "throw")
+  c++  '("const" "noexcept" "volatile")
   objc '("const" "volatile"))
 
+(c-lang-defconst c-opt-type-modifier-prefix-key
+  ;; Adorned regexp matching `c-type-modifier-prefix-kwds', or nil in
+  ;; languages without such keywords.
+  t (and (c-lang-const c-type-modifier-prefix-kwds)
+	 (c-make-keywords-re t (c-lang-const c-type-modifier-prefix-kwds))))
+(c-lang-defvar c-opt-type-modifier-prefix-key
+	       (c-lang-const c-opt-type-modifier-prefix-key))
+
+(c-lang-defconst c-type-modifier-kwds
+  "Type modifier keywords.  These can occur almost anywhere in types except
+at the start, but they don't build a type of themselves.  Unlike the keywords
+on `c-primitive-type-kwds', they are fontified with the keyword face and not
+the type face."
+  t (c-lang-const c-type-modifier-prefix-kwds)
+  c++ (append (c-lang-const c-type-modifier-prefix-kwds) '("throw")))
+
 (c-lang-defconst c-opt-type-modifier-key
   ;; Adorned regexp matching `c-type-modifier-kwds', or nil in
   ;; languages without such keywords.