Crash : Deletion Of Group Output Node of a Nodegroup Connected to Displacement Socket
Closed, ResolvedPublic


System Information
Ubuntu 16.04 64 bits Nvidia Titan Black

Blender Version
Broken: 2.79 and master f34e03d
Worked: (optional)

Short description of error
When 3D View uses Material viewport shading type, if a Group Output node of a nodegroup that is connected to Displacement socket of Material Output node is deleted : Blender crashes.
It does not happen if viewport shading type is different or if connection to Displacement socket is undone.

Bug reported on iirc and blender.stackexchange

Exact steps for others to reproduce the error
In attached .blend file, delete Group Output node.

I can confirm this with Windows .2.79

Does not generate anything when used with blender > crashtest.txt

I'm getting this in the debugger.

The thread 0x3ed8 has exited with code 0 (0x0).
The thread 0x4300 has exited with code 0 (0x0).
Exception thrown: read access violation.
node was nullptr.