Bug 444017

Summary:	Selecting on vector selection mode causes boundary of selection to be deleted
Product:	[Applications] krita	Reporter:	Breno Sakaguti <brenosakaguti>
Component:	Tools/Selection	Assignee:	Krita Bugs <krita-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	halla, tomtomtomreportingin
Priority:	NOR	Keywords:	triaged
Version First Reported In:	4.4.8
Target Milestone:	---
Platform:	Appimage
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Breno Sakaguti 2021-10-19 06:45:51 UTC

SUMMARY
Using a selecting tool with vector selection turned mode (on the elliptical selection, polygonal selection or freehand selection tools) causes a thin line of pixels around the boundary of the selection to be deleted.

STEPS TO REPRODUCE
1. Fill any image with a non-white color (https://imgur.com/oKw0SQ5)
2. Select a region of the image using (e.g.) freehand select tool (https://imgur.com/xRIk0aF)
3. Using the move tool (T), move the selection one pixel to the left and then one pixel to the right (https://imgur.com/M5TfgtJ)

OBSERVED RESULT
The image has a thin white contour around it, showing which pixels were deleted (https://imgur.com/dktlf2B)

EXPECTED RESULT
No pixels around the boundary should be removed

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 Halla Rempt 2021-10-19 07:39:56 UTC

That's the antialiasing of the selection. If I move the selection back into its exact original location, there is no contour.

Comment 2 Breno Sakaguti 2021-10-19 16:39:01 UTC

(In reply to Halla Rempt from comment #1)
> That's the antialiasing of the selection. If I move the selection back into
> its exact original location, there is no contour.

That hasn't been my experience. The steps I described should leave the image exactly as started, but there's still a white border around the region afterwards.

Comment 3 tomtomtomreportingin 2021-10-19 17:33:28 UTC

Perhaps this could be considered a duplicate of https://bugs.kde.org/show_bug.cgi?id=442191 , however this concerns the Move tool and not the Transform tool. 

The behavior that Breno describes does seem a bit buggy. For example, creating a vector selection in a sea of black and then simplying clicking the selection with the Move tool will product artifacts on the edges.