white left upper corner when viewing image at a particular scale

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

When I view the edited image at a particular scale lower than iamge fit the left upper image corner casts a white shadow that disappears again when I zoom out or in.

Steps to reproduce

1. open any image with lens correction using correction method = embedded metadata
2. add local contrast with shadows=0 (or 200 - the further away from 100 the more promiment the effect is)
3. scroll one step out
4. disable filmic / sigmoid to emhasize the effect more
5. set the exposure mask mode to multiply to emhasize the effect more

Expected behavior

the image should look no different than at any other scale

Logfile | Screenshot | Screencast

Commit

No response

Where did you obtain darktable from?

distro packaging

darktable version

5.2.1

What OS are you using?

Linux

What is the version of your OS?

Archlinux 1.0

Describe your system

wayland - sway

Are you using OpenCL GPU in darktable?

None

If yes, what is the GPU card and driver?

tried rusticl - radeonsi (amd iGPU), but is the same without opencl

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

same result with images from both automatic and manual lens (providing no metadata)

Both images with darktable xmp edits in case it is related to some camera metadata (X-T2): https://www.mediafire.com/file/llryr0hkvmmbqpd/whie_corner.zip/file (Note: I typoed the filename)

I verified this is not an issue with SOOC JPEGs

Reproduce the artifact with lens correction using embedded metadata, local contrast, and the specified zoom and mask settings, comparing nearby scales. Trace the scale-dependent image rendering path and verify the white upper-left corner no longer appears at any scale; no source file or test is identified in the report.