[Bug fortran/50375] gfortran must complain on NULL() ambiguity without MOLD

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50375

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-09-13 13:55:13 UTC ---
Created attachment 25262
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25262
Draft patch

This patch handles NULL() properly, including passing it to optional
nonpointer, nonallocatable dummies.

Caveat: It currently prints two messages - I don't want to have the second one.

      call gen(null())
               1
Error: MOLD= required in NULL() argument at (1): Ambiguity between specific
functions s2 and s1

      call gen(null())
                      1
Error: There is no specific subroutine for the generic 'gen' at (1)