[Bug fortran/48786] [4.6/4.7 Regression][OOP] Generic ambiguity check too strict for polymorphic dummies

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48786

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-04-29 16:04:45 UTC ---
Mini analysis:

(In reply to comment #3)
> ==30150== Invalid read of size 8
> ==30150==    at 0x4CB104: gfc_compare_derived_types (interface.c:409)

The problem is that the second argument of gfc_compare_derived_types is
derived2 == NULL.


> The issue is that the result variable is not properly initialized; from the
> dump:
> 
>   struct __class_points2d3d_Point2d_a __result_add_vector_2d;
>   if (__result_add_vector_2d._data != 0B)

That's odd as it should be handled in trans-decl.c around line 3524
(gfc_trans_deferred_vars).