[Pkg-gmagick-im-team] Bug#845196: Check return of write function

[Bastien ROUCARIES]

Package: src:imagemagick
version: 8:6.8.9.9-5+deb8u5
Severity: important
Tags: patch security
X-Debbugs-CC: secure-testing-team at lists.alioth.debian.org
control: found -1 8:6.7.7.10-5+deb7u7

Imagemagick write path does not check return of fputc.

Therefore it could return success of conversion instead of faillure.

This could be a problem for php-magick

Bastien