videobox: segmentation fault when changing direction properties

Submitted by Dimitrios Katsaros

Link to original bug (#783585)

Description

Created attachment 353446
demo app for triggering seg faluts

I am trying to use the videobox element to have a video output that shows video in its actual pixel size, i.e. 1 to 1 pixel to screen ratio. I want the user to be able to slide the visible region across the image. Thus I am using the videobox element, connecting the top, bottom, left and right properties to sliders. When using the sliders to reposition the visible region, videobox segments. It would seem that rapidly changing the values triggers a race condition in the orc code.

I have attached a simple app that seems to be triggering the segment for me. It is a bit make shift so if it doesn't work please ping me so we can figure out why. With this app I also seem to be triggering SIGABRT as well. It might be the same issue or another one.

Attachment 353446, "demo app for triggering seg faluts":
demo.c