[BUG] [EDITOR] Selecting pieces sometimes moves them

[Proxima]

Firstly, if the grid is on, then clicking on a piece to select it makes it jump to the grid. This is bad because the user may want to select the piece to make copies of it without changing its current position; and if they do want to adjust it to the grid they have the option of dragging it a short way and then back to its original position.

Secondly, again only if the grid is on, clicking on a piece with a negative X- or Y-coordinate, even if it is aligned with the grid, makes it jump by one grid-tile. This part is definitely a bug

[Nepster]

When you have had time to test the new editor version, please tell me whether the first part is still an issue.

PS: I know that the bug in the second part is still in the editor.

[namida]

Can confirm both parts of this remain an issue in the latest editor code.

Initial investigation points to it relating to the "on release mouse" code, in particular, that it might not be correctly distinguishing between a click vs a (very short) drag.

[namida]

Both issues (including the less-obvious variant of the 2nd one, where the position is biased slightly towards the lower-right when dragging a piece with negative coordinates) fixed in commit 79c686b.