[Lua Script] Sprite:selection does not work after executing app.command.MoveMask

Bug Reports
1

After moving the selection with the “MoveMask” command, the following three scripts do not work correctly (no error occurs and nothing changes).
However, if I call the “DeselectMask” command, it will work correctly.

I think it’s probably a bug.

  1. Change the selection by calling the Selection:select method.
local sprite = app.activeSprite
local bounds = Rectangle(0, 0, 10, 10)
sprite.selection:select(bounds)

app.command.MoveMask{
    target='content',
    direction='down',
    units='pixel',
    quantity=10,
    wrap=false
  }

-- app.command.DeselectMask{} --Uncommenting this line will make it work as expected

local newBounds = Rectangle(0, 0, 20, 20)
sprite.selection:select(newBounds) -- not working
  1. Call the Selection:deselect method to deselect the selection.
local sprite = app.activeSprite
local bounds = Rectangle(0, 0, 10, 10)
sprite.selection:select(bounds)

app.command.MoveMask{
    target='content',
    direction='down',
    units='pixel',
    quantity=10,
    wrap=false
  }

sprite.selection:deselect() -- not working but app.command.DeselectMask is working
  1. Assign a value to Selection.origin to move the selection.
local sprite = app.activeSprite
local bounds = Rectangle(0, 0, 10, 10)
sprite.selection:select(bounds)

app.command.MoveMask{
    target='content',
    direction='down',
    units='pixel',
    quantity=10,
    wrap=false
  }

-- app.command.DeselectMask{} --Uncommenting this line will make it work as expected
-- sprite.selection:select(bounds)
sprite.selection.origin = Point(0, 0) -- not working

Thanks for reading!

2

I have just encountered this as well trying to write a script to shuffle some pixels around in 1.3.2 on linux using the installer version.

local spr = app.sprite
if not spr then return end

local sel = spr.selection
if sel.isEmpty then return end

local step = 2

local x = sel.bounds.x
local y = sel.bounds.y
local w = sel.bounds.w
local h = sel.bounds.h

app.transaction(
	"Skew",
	function()
		for i = x, x + w - 1, step do
			spr.selection:select(Rectangle({i, y, step, h}))

			app.command.MoveMask {
				target="content",
				wrap=false,
				direction="up",
				units="pixel",
				quantity=i / step
			}

			-- app.command.DeselectMask()
		end
	end)

Without the deselect mask command Aseprite just moves the first selection and crashes when I do any kind of operation on the sprite afterwards. Sometimes an error pops up just before the crash:

An error has occured.

Details:
Cannot modify the sprite.
It is being used by another command.
Try again.

Cannot modify the sprite when we are undoing/redoing an action.

Internal details:
- Message type: 12
- Editor state: N3app17MovingPixelsStateE

Unless I’m doing something fundamentally wrong I also think it’s a bug.