Bug#647425: g++-4.6: warn_unused_result error triggerd even if casted

[Cajus Pollmeier <cajus@naasa.net>]

Package: g++-4.6
Version: 4.6.2-3
Severity: normal

Dear Maintainer,

while preparing the next upload for the qpid package, I've stumbled 
over
a changed behaviour in handling unused results.

The code that is rising errors:

   (void) ::lockf(f, F_ULOCK, 0);

If I change it to some construct like:

   size_t foo;
   foo = ::lockf(f, F_ULOCK, 0);
   (void)foo;

works, but is a bit hackish.

The complete build log can be found at:

  https://ferdi.naasa.net/url/cajus/qpid-cpp_0.12-2_amd64.build

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.0.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages g++-4.6 depends on:
ii  gcc-4.6             4.6.2-3
ii  gcc-4.6-base        4.6.2-3
ii  libc6               2.13-21
ii  libgmp10            2:5.0.2+dfsg-2
ii  libmpc2             0.9-4
ii  libmpfr4            3.1.0-2
ii  libstdc++6-4.6-dev  4.6.2-3
ii  zlib1g              1:1.2.3.4.dfsg-3

g++-4.6 recommends no packages.