Re: Warning fix

[Owen Taylor <otaylor redhat com>]

Pavel Roskin <proski gnu org> writes:

> Hello!
> 
> There is a minor bug in version 1.2.10. The definition of GTK_IS_OBJECT in
> gtk/gtkobject.h contains:
> 
> (object) != NULL
> 
> This causes a warning (comparison between pointer and integer) with
> gcc-2.96 (RedHat 7.1) when an integer is passed to GTK_OBJECT. GTK_OBJECT
> takes case to cast the argument, but GTK_IS_OBJECT doesn't.
> 
> Either compare with 0 or cast it to (void *). The same applies to
> GTK_IS_OBJECT_CLASS.

Err, GTK_IS_FOO() tests if a particular pointer is a GtkFoo.
There is absolutely no chance that an integer is a pointer to
a GtkFoo, so calling GTK_IS_FOO() on an integer is just an error.
Most likely it will cause a segfault, because the tests will
try to interpret the integer as a pointer.

(In fact, if calling GTK_IS_OBJECT is legal at all, it will
return TRUE, since you can only call GTK_IS_OBJECT on objects
inheriting from GtkObject.)

I think the compiler is simply catching a bug in your code.

Regards,
                                        Owen