When Ctrl+Z undoes a movement, remove that movement form the movement history as well (resolves #64)

src/movement_tracking.js

@@ -1,6 +1,6 @@
 import {measureDistances} from "./compatibility.js";
 import {recalculate, updateCombatantDragRulerFlags} from "./socket.js";
-import {getTokenShape, zip} from "./util.js";
+import {getTokenShape, isClose, zip} from "./util.js";
 
 function initTrackingFlag(combatant) {
 	const initialFlag = {passedWaypoints: [], trackedRound: 0};
@@ -81,6 +81,20 @@ export function getMovementHistory(token) {
 	return dragRulerFlags.passedWaypoints ?? [];
 }
 
+export async function removeLastHistoryEntryIfAt(token, x, y) {
+	const history = getMovementHistory(token);
+	if (history.length === 0)
+		return;
+	const entry = history[history.length - 1];
+	if (!isClose(x + token.w / 2, entry.x, 0.1) || !isClose(y + token.h / 2, entry.y, 0.1)) {
+		return;
+	}
+	history.pop();
+	const combat = game.combat;
+	const combatant = combat.getCombatantByToken(token.id);
+	await updateCombatantDragRulerFlags(combat, [{_id: combatant.id, dragRulerFlags: combatant.data.flags.dragRuler}]);
+}
+
 export async function resetMovementHistory(combat, combatantId) {
 	const combatant = combat.combatants.get(combatantId);
 	const dragRulerFlags = combatant.data.flags.dragRuler;