libraries/gstreamermm: Patch for gcc >= 7.x.

Signed-off-by: Matteo Bernardini <ponce@slackbuilds.org>

libraries/gstreamermm/fix_warnings.patch

@@ -0,0 +1,15 @@
+Author: Marcin Kolny <marcin.kolny@gmail.com>
+Description: Fix warnings
+Origin: https://git.gnome.org/browse/gstreamermm/commit/gstreamer/gstreamermm/check.cc?id=c5006faf05bc4b46767d30f42bcb6157836b7540
+Last-update: 2016-09-25
+--- a/gstreamer/gstreamermm/check.cc
++++ b/gstreamer/gstreamermm/check.cc
+@@ -54,7 +54,7 @@
+ 
+     element = ElementFactory::create_element (factory, factory);
+ 
+-    ThrowIf (element, "Could not create a '" + factory + "' element");
++    ThrowIf (!!element, "Could not create a '" + factory + "' element");
+     CheckRefCount (element->gobj(), factory, 1);
+ 
+     return element;

libraries/gstreamermm/gstreamermm.SlackBuild

@@ -69,6 +69,9 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
  -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
+# Needed for gcc >= 7.x - Thanks to opensuse
+patch -p1 < $CWD/fix_warnings.patch
+
 CFLAGS="$SLKCFLAGS" \
 CXXFLAGS="$SLKCFLAGS -std=c++11" \
 ./configure \