[Rlib-users] GCC4 warning fixes part4

[Zoltan B. <zb...@du...>]

Hi,

here's the next part. Changelog:

***********************************************************
Silence warnings in datasource.c. The original code gave these
kinds of warnings on GCC4:
warning: ISO C forbids conversion of function pointer to object pointer t=
ype
warning: ISO C forbids initialization between function pointer and 'void =
*'
warning: ISO C forbids assignment between function pointer and 'void *'
The above warnings sound serious but on the other hand, explicitly
casting the address of a function pointer to a (gpointer *) gave this
warning on older GCCs:
warning: dereferencing type-punned pointer will break strict-aliasing rul=
es
Aliasing function pointers to gpointer using unions solves this, using
   union {
     gpointer ptr;
     void (*function)(void);
   }
allows the assignment to the gpointer and calling function() without
warnings.
***********************************************************

Best regards,
Zolt=E1n B=F6sz=F6rm=E9nyi