Bug 419830

Summary: Incorrect Thumbnail on both Group/Raster layer
Product: [Applications] krita Reporter: Nick Mok <ex_hunter>
Component: DockersAssignee: Krita Bugs <krita-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: normal CC: ahab.greybeard, penguinflyer2222, tamtamy.tymona
Priority: NOR    
Version: nightly build (please specify the git hash!)   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed In:
Attachments: Layer thumbnails for initial painting
Layer Thumbnails after painting and erasing content

Description Nick Mok 2020-04-08 08:10:14 UTC
SUMMARY
Thumbnail bounding box became incorrect after some manipulation.


STEPS TO REPRODUCE (case 1 - Group Layer)
1. Create a group layer containing two pixel layers (A,B) with some shapes in it.
2. Pick a pixel layer A
3. "Edit" > "Fill with Background/Foreground color". (Now group Thumbnail show full canvas)
4. "Edit" > "Clear" that pixel layer A. 
5. Observe that Group thumbnail still showing full canvas.

STEPS TO REPRODUCE (case 2 - Pixel Layer)
1. Draw anything
2. Flip the layer horizontally using Transform's Mirror function.


OBSERVED RESULT
Bounding box is showing the full canvas instead of clipped to the visible pixels.

EXPECTED RESULT
Group/Pixel Layer should show correct clipped content instead of full canvas or or distorted / incorrect bounding box.

SOFTWARE/OS VERSIONS

Tested on: 
-krita 2.4.9 
-krita-nightly-x64-v4.3.0-prealpha-2452-gea68cde0f9.zip

Windows: 10

ADDITIONAL INFORMATION

https://krita-artists.org/t/bug-group-layer-thumbnail-not-clipped-under-certain-situation/5169
Comment 1 Ahab Greybeard 2020-04-08 10:16:59 UTC
Created attachment 127381 [details]
Layer thumbnails for initial painting

I can confirm this for the 4.2.9 appimage.
I attach Initial-Thumbnails.png whuch shows correct thumbnail images.

After painting a small red blob in the top right corner of Layer 5 and then carefully erasing that painted blob, the thumbmails for Layer 5 and the group Layer 6 shows thumbnails as if the erased blob was still there as shown in:
Shifted-Thumbnails.png attached.

Setting to Confirmed
Comment 2 Ahab Greybeard 2020-04-08 10:17:43 UTC
Created attachment 127382 [details]
Layer Thumbnails after painting and erasing content
Comment 3 Tiar 2020-11-07 20:08:47 UTC
It's not really the thumbnail's fault, but the Fill Tool algorithm - filling everything and then cutting off the unimportant parts, but still changing the boundary of the layers - and the general reluctance of Krita to trim off empty image tiles (sections).
Comment 4 Freya Lupen 2023-06-20 22:59:26 UTC

*** This bug has been marked as a duplicate of bug 459273 ***