System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.38
Blender Version
Broken: version: 2.91.0, branch: master, commit date: 2020-11-25 08:34, hash: rB0f45cab862b8
Worked: (newest version of Blender that worked as expected) version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: rB3e85bb34d0d7
Short description of error
The UV Smart Project Operator has been refactored into C code as per https://developer.blender.org/D8311
In the process the operator has been changed so it no longer works in object mode, breaking any add-on which calls it in object mode. This has not been documented in the release notes and isn't mentioned anywhere in the diff.
Returns the usual RuntimeError: Operator bpy.ops.uv.smart_project.poll() failed, context is incorrect
Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]
2.90.1 Run uv smart project in object mode on default cube - Success
2.91 Run uv smart project in object mode on default cube - Fail