316fe67295
When strokes from to different layers get joined together, if one layer had the `resolution` attribute and the other did not. The new `resolution` attribute would be left with uninitialized values and then a crash would happen. This fixes this by filling all attributes that didn't exist with their default value. This also ensures that when strokes are removed, the drawing is tagged as dirty. Pull Request: https://projects.blender.org/blender/blender/pulls/147948