Fix stack2 param

Fix stack2 amount count
Fix stack2 sign recognition for y & z

worldedit/manipulations.lua

@@ -286,7 +286,7 @@ worldedit.stack2 = function(pos1, pos2, direction, amount, finished)
 	local i = 0
 	local translated = {x=0,y=0,z=0}
 	local function nextone()
-		if i <= amount then
+		if i < amount then
 			i = i + 1
 			translated.x = translated.x + direction.x
 			translated.y = translated.y + direction.y

worldedit_commands/init.lua

@@ -641,7 +641,7 @@ minetest.register_chatcommand("/stack2", {
 		end
 		repetitions = tonumber(repetitions)
 
-		local x, y, z = incs:match("([+-]?%d+) ([+-]%d+) ([+-]%d+)")
+		local x, y, z = incs:match("([+-]?%d+) ([+-]?%d+) ([+-]?%d+)")
 		if x == nil then
 			worldedit.player_notify(name, "invalid increments: " .. param)
 			return