Created attachment 154664 [details] Observed result SUMMARY Layer thumbnails allow to quickly identify layers. Wen drawing on a small portion of the canvas, the thumbnails are zoomed on them so they can still display something meaningful to the artist. The problem is brush strokes, even when totally empty, change the bound of the image on the layer: When you look at the thumbnail, it looks empty or very zoomed out and unusable. STEPS TO REPRODUCE 1. Make a big canvas and add an empty layer on top (checkerboards) 2. Make a small mark in a corner of the canvas. Note the layer thumbnail is nice and zoomed correctly (first attachement) 3. Turn eraser mode on a classic pixel brush. Make an erasing mark on the opposite side of the canvas. The thumbnail now zoomed out to take the whole canvas. Your real content (the first little mark on the first corner, is undistinguishable) Done on a macbook pro 16" with M1 processor with macOS 12.6.1 (21G217)
I cannot reproduce this behavior when following the steps make sure you completely erase the pixel data or else it wont "reframe", barely visible "paint" is "paint". Use rectangular marquee then press <delete> for step 3, this ensures it will "reframe". Erasing with brush, depending on flow and opacity will make it more difficult to ensure there is indeed no data in the erased area (you can Ctrl + click layer thumbnail to select those almost transparent pixels to reveal them).
It's not related with barely visible pixels I would have missed. You can even paint with the eraser, it will change the bounds while there is no paint info on the area.
Reopening if I may so.
I see why I can't reproduce it locally, the bug was already reported and is fixed on master. We somehow forgot to cherrypick the last patch into the stable branch after the first patch was reverted. The fix will have to land in 5.2 as 5.1.4 was the last bugfix release for 5.1 series afaik *** This bug has been marked as a duplicate of bug 459273 ***