Allow passing a NULL msg to Jim_WrongNumArgs

[aryler]

Untested!

--- jim.c.orig  Wed Jun  6 16:05:13 2018
+++ jim.c       Wed Jun  6 16:05:27 2018
@@ -11183,7 +11183,7 @@ void Jim_WrongNumArgs(Jim_Interp *interp, int argc, Ji
 
     listObjPtr = Jim_NewListObj(interp, argv, argc);
 
-    if (*msg) {
+    if (msg && *msg) {
         Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, msg, -1));
     }
     Jim_IncrRefCount(listObjPtr);

[msteveb]

Why?

[aryler]

• When there's nothing to say.
• Line up behaviour a bit with Tcl (saves an #ifdef in Tcl/Jim compatible code).
• NULL is smaller than "", since "" requires a pointer and a '\0' ?

[aryler]

You can see what I mean here:
http://chiselapp.com/user/stwo/repository/tjpledge/artifact?ln=100-106&name=ea0b14db3caccd06
It would be nice to be able to write that one one line, like normal.

[msteveb]

OK. The consistency argument is convincing. Done.