**System Information**
Operating system: Linux-4.13.10-041310-generic-x86_64-with-debian-stretch-sid 64 Bits
Graphics card: GeForce GTX 1050/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 390.67
**Blender Version**
Broken: version: 2.81 (sub 15), branch: master, commit date: 2019-10-24 19:00, hash: `rB892c3891ed0b`
**Short description of error**
In the attached blend, I have a few objects and materials. In the script in the text editor I'm batch renaming the materials.
Whenever I call this script and the 3d view is in lookdev or eevee rendered shading, I'm seeing blender freezing for a few seconds, AFTER the renaming concluded.
I'm not chaning any material parameters. There's is no indication that the shaders are recompiling. It's just the material names that changed.
I am using bump nodes in some of the materials, so it may be again related to [[ https://developer.blender.org/T70766 | this previous issue ]] I've submitted recently.
Removing all node groups using the bump node, leads to no more freezing.
Renaming node trees in a similar fashion, will also cause the freeze however, even if only node tree's that don't contain a bump node are renamed.
[[ https://www.youtube.com/watch?v=3Lnjvwi64tw | video demo ]]
{F7869964}
**Exact steps for others to reproduce the error**
* open the blend file in 2.81
* in with eevee shading, run the scrip, notice how the terminal says renaming is finished
* immedately try rotatiing he viewport, notice how Blender is unresponsive for a few seconds
* repeard in solid or rendered cyclices shading
* notice how there's no freeze