svn commit: samba r17645 - in branches/SAMBA_4_0/source/lib/talloc: .

[tridge at samba.org]

Metze,

 > thanks! Can you merge that to talloc_reference() and all other places
 > that uses that trick too.

It's not needed for talloc_reference(). It's basically a bug (or
mis-feature perhaps) in the gcc code that decides if a warning should
be generated for constructing a value that is not used. Normally this
warning is only emitted if you enable a special attribute. With the
macro we used to make talloc_steal() type safe, it was being emitted
every time.

It doesn't matter for talloc_reference(), as we actually do want to
always check the return value for that function, as it can fail due to
system resources (ie. it allocates memory). talloc_steal() can only
fail due to programmer error, so not checking its return value is
normal, just like functions like memmove(). However, unlike memmove(),
gcc was generating a warning when you didn't check the return value of
talloc_steal().

A gcc developer offered to work up a patch to gcc to avoid the
problem, but its easier to just avoid it with that ugly workaround, as
it means we don't have to upgrade gcc everywhere.

Cheers, Tridge