ocamldoc: fix printing of (::)

Changes

@@ -373,6 +373,9 @@ Working version
 - #8747, #9709: incorrect principality warning on functional updates of records
   (Jacques Garrigue, report and review by Thomas Refis)
 
+- #9421, #9427: fix printing of (::) in ocamldoc
+  (Florian Angeletti, report by Yawar Amin, review by Damien Doligez)
+
 - #9469: Better backtraces for lazy values
   (Leo White, review by Nicolás Ojeda Bär)
 

ocamldoc/odoc_sig.ml

@@ -388,8 +388,14 @@ module Analyser =
               | Cstr_record l ->
                   Cstr_record (List.map (get_field env name_comment_list) l)
             in
+            let vc_name = match constructor_name with
+              | "::" ->
+                  (* The only infix constructor is always printed (::) *)
+                  "(::)"
+              | s -> s
+            in
             {
-              vc_name = constructor_name ;
+              vc_name;
               vc_args;
               vc_ret =  Option.map (Odoc_env.subst_type env) ret_type;
               vc_text = comment_opt