Ubuntu 14.04 / GTX 760
Broken: 2.74 RC2
Short description of error
Blender crashes when nodes are muted between Separete RGBA and Combine RGBA (those nodes also muted).
This is an example that makes Blender crash : http://img11.hostingpics.net/pics/497017compobug.png
Same node setup was working fine on 2.73 version.
Each nodes can be muted without problem but everything in the same time cause the issue.
Exact steps for others to reproduce the error
Open Blender, make a render, go to the compositor, create a Separete RGBA and Combine RGBA nodes, connect them and put anything between it (math, color balance). Display the result, mute those three nodes and it always crash on my computer.
http://vincentgires.com/divers/blender_bug/compo_mute_bug_2.74.blend (this is the screenshot file)