SUMMARY When there is no global selection, creating a new local selection will cause an exception STEPS TO REPRODUCE 1. Create a new local selection and switch to it 2. Use the rectangle selection tool to draw a few squares 3. Return to the layer and find several rectangular selections. But they do not have a limiting effect EXPECTED RESULT After creating a new local selection，a selection should appear that envelops the canvas.Then everything is fine
I can confirm the observations made in this report for the Nov 03 5.1.0-prealpha (git 5214230) and 4.4.8 appimages on Debian 10. It's also the case for the 4.4.8 appimage. The situation has varous sources of confusion associated with the detailed behaviour of the selection masks. For the report as originally made: If there is no Global selection mask displayed, a local selection mask is created as all white, i.e. all selected. Thus, any selection made with Add will not affect the mask, which I believe is what happened when you made several selection rectangles on the local selection mask. However, the selection tool made selections are shown as dotted outlines on the paint layer, which they should not be. If a Global mask is selected to be displayed then it is created as black meaning that nothing is selected and so nothing can be painted, even if the paint layer had no previous 'limiting' selections. Then, if a Local mask is created, it will be created as all black and the Global mask will be removed.
5.2.3 This issue still exists. I would like to provide some additional clarification here: If you drag a 'global selection mask' under a layer to make it a 'local selection mask', it will not have any problems. If you create a "Local selection mask" under a layer, it will display a completely white mask. Then 1. If you have a pen drawing on the mask, it will have normal functionality, but abnormal dashed contours. If you use the selection tool, it will display a normal dashed outline, but it has no practical effect I guess changing the default mask to all black would be better