projectm: ensure that the GL context is attached

Author: tguillem

modules/visualization/projectm.cpp

@@ -280,7 +280,11 @@ static void *Thread( void *p_data )
     projectM::Settings settings;
 #endif
 
-    vlc_gl_MakeCurrent( gl );
+    if( vlc_gl_MakeCurrent( gl ) != VLC_SUCCESS )
+    {
+        msg_Err( p_filter, "Can't attach gl context" );
+        return NULL;
+    }
 
     /* Work-around the projectM locale bug */
     loc = newlocale (LC_NUMERIC_MASK, "C", NULL);