Prevent unavailable color switching crash

room.lua

@@ -341,21 +341,21 @@ function Room:movePlayer(key)
 end
 
 function Room:switchPlayerColor(color)
-	local canSwitch
+	-- Number keys can request a colour the player has not collected yet.  Do
+	-- nothing in that case: there is no corresponding player object to switch
+	-- to (or use as the sound source).
+	local targetPlayer = self.player[color]
+	if not targetPlayer then return false end
 
-	if self:onlyColorIsActive(color) then
-		canSwitch = false
-	else
-		for _, c in pairs(self:getPossibleColors()) do
-			if c == color then
-				self:setActiveColor(c, true)
-			else
-				self:setActiveColor(c, false)
-			end
+	local canSwitch = not self:onlyColorIsActive(color)
+	if canSwitch then
+		for _, c in ipairs(self:getPossibleColors()) do
+			self:setActiveColor(c, c == color)
 		end
 	end
 
-	self.player[color]:playSwitchSound(canSwitch)
+	targetPlayer:playSwitchSound(canSwitch)
+	return canSwitch
 end
 
 function Room:setActiveColor(color, bool)