bug: Gstreamer pipeline is not closed when starting it was unsuccessful

Hi,

i am working on an open frameworks app (0.9.3) in Ubuntu which is supposed to display a presentation of different pictures and videos. After running my open frameworks app for a few hours it crashed with a "to many open files error" I started investigating and found out there are tons of unix sockets opened and never closed again.

How to reproduce:
Create a of app which tries to playback video using gstreamer. Then tell it to load a video that does not exist (or where the app has no reading rights). Everey time the app tries to load the video, a new unix socket will be created but never closed. Check using lsof -r 1 -p xxxx | grep socket where xxxx is your apps PID.

I looked into the code of ofGstVideoPlayer.cpp and think the error is in the load function:
(starting at line 205)

if(isInitialized()){
        gst_element_set_state (videoUtils.getPipeline(), GST_STATE_READY);
        if(!bIsStream){
            gst_element_get_state (videoUtils.getPipeline(), NULL, NULL, -1);
        }
        internalPixelFormat = OF_PIXELS_NATIVE;
        bIsAllocated = false;
        videoUtils.reallocateOnNextFrame();
        g_object_set(G_OBJECT(videoUtils.getPipeline()), "uri", name.c_str(), (void*)NULL);
        gst_element_set_state (videoUtils.getPipeline(), GST_STATE_PAUSED);
        if(!bIsStream){
            gst_element_get_state (videoUtils.getPipeline(), NULL, NULL, -1);
            return allocate();
        }else{
            return true;
        }
    }else{
        ofGstUtils::startGstMainLoop();
        return createPipeline(name) &&
                videoUtils.startPipeline() &&
                (bIsStream || allocate());
    }

in the "else"-part, a new piepeline is created, but if startPipeline() fails, bLoaded will remain false, so the created pipeline is never released.

I'm working on a fix, but it is kinda difficult because the pipeline itself belongs to the ofGstVideoUtils class and calling close wont do the trick (since loaded is false). Also, what else needs to be done at this point to properly clean up everything thats already loaded?

Start in ofGstVideoPlayer.cpp at load(), then trace createPipeline(), ofGstVideoUtils::startPipeline(), and the existing close path. Reproduce repeated attempts to load an inaccessible video and verify that failed starts release the created pipeline and do not leave Unix sockets open.