Bug#674917: libc6-dev: mblen is erroneously marked warn_unused_result

[Antti-Juhani Kaijanaho <ajk@debian.org>]

Package: libc6-dev
Version: 2.13-32
Severity: normal

GCC documentation states:

  The warn_unused_result attribute causes a warning to be emitted if a caller
  of the function with this attribute does not use its return value. This is
  useful for functions where not checking the result is either a security
  problem or always a bug, such as realloc.

However, so far as I can see, ignoring the return value of mblen is never a
security problem and is sometimes appropriate (the first call to the function
is often mblen(NULL, 0), the result value of which is usually of no interest).

(Debian's use of -D_FORTIFY_SOURCE=2 and the common policy of using -Werror
together make this a noncosmetic issue.)

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 3.4.0-ibid-1 (SMP w/2 CPU cores; PREEMPT)
Locale: LANG=fi_FI.UTF-8, LC_CTYPE=fi_FI.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages libc6-dev depends on:
ii  libc-dev-bin    2.13-32
ii  libc6           2.13-32
ii  linux-libc-dev  3.2.18-1

Versions of packages libc6-dev recommends:
ii  gcc [c-compiler]      4:4.7.0-6
ii  gcc-4.4 [c-compiler]  4.4.7-1
ii  gcc-4.5 [c-compiler]  4.5.3-12
ii  gcc-4.6 [c-compiler]  4.6.3-5
ii  gcc-4.7 [c-compiler]  4.7.0-9

Versions of packages libc6-dev suggests:
ii  glibc-doc     <none>
ii  manpages-dev  3.40-0.1

-- no debconf information