fix broken updateEvent method

src/EventManager.js

@@ -23,6 +23,7 @@ function EventManager(options) { // assumed to be a calendar
 	t.renderEvent = renderEvent;
 	t.removeEvents = removeEvents;
 	t.clientEvents = clientEvents;
+	t.mutateEvent = mutateEvent;
 	
 	
 	// imports
@@ -30,7 +31,6 @@ function EventManager(options) { // assumed to be a calendar
 	var getView = t.getView;
 	var reportEvents = t.reportEvents;
 	var getEventEnd = t.getEventEnd;
-	var mutateEvent = t.mutateEvent;
 	
 	
 	// locals
@@ -477,6 +477,173 @@ function EventManager(options) { // assumed to be a calendar
 
 		return out;
 	}
+
+
+
+	/* Event Modification Math
+	-----------------------------------------------------------------------------------------*/
+
+
+	// Modify the date(s) of an event and make this change propagate to all other events with
+	// the same ID (related repeating events).
+	//
+	// If `newStart`/`newEnd` are not specified, the "new" dates are assumed to be `event.start` and `event.end`.
+	// The "old" dates to be compare against are always `event._start` and `event._end` (set by EventManager).
+	//
+	// Returns a function that can be called to undo all the operations.
+	//
+	function mutateEvent(event, newStart, newEnd) {
+		var oldAllDay = event._allDay;
+		var oldStart = event._start;
+		var oldEnd = event._end;
+		var clearEnd = false;
+		var newAllDay;
+		var dateDelta;
+		var durationDelta;
+
+		// if no new dates were passed in, compare against the event's existing dates
+		if (!newStart && !newEnd) {
+			newStart = event.start;
+			newEnd = event.end;
+		}
+
+		// NOTE: throughout this function, the initial values of `newStart` and `newEnd` are
+		// preserved. These values may be undefined.
+
+		// detect new allDay
+		if (event.allDay != oldAllDay) { // if value has changed, use it
+			newAllDay = event.allDay;
+		}
+		else { // otherwise, see if any of the new dates are allDay
+			newAllDay = !(newStart || newEnd).hasTime();
+		}
+
+		// normalize the new dates based on allDay
+		if (newAllDay) {
+			if (newStart) {
+				newStart = newStart.clone().stripTime();
+			}
+			if (newEnd) {
+				newEnd = newEnd.clone().stripTime();
+			}
+		}
+
+		// compute dateDelta
+		if (newStart) {
+			if (newAllDay) {
+				dateDelta = dayishDiff(newStart, oldStart.clone().stripTime()); // treat oldStart as allDay
+			}
+			else {
+				dateDelta = dayishDiff(newStart, oldStart);
+			}
+		}
+
+		if (newAllDay != oldAllDay) {
+			// if allDay has changed, always throw away the end
+			clearEnd = true;
+		}
+		else if (newEnd) {
+			durationDelta = dayishDiff(
+				// new duration
+				newEnd || t.getDefaultEventEnd(newAllDay, newStart || oldStart),
+				newStart || oldStart
+			).subtract(dayishDiff(
+				// subtract old duration
+				oldEnd || t.getDefaultEventEnd(oldAllDay, oldStart),
+				oldStart
+			));
+		}
+
+		return mutateEvents(
+			clientEvents(event._id), // get events with this ID
+			clearEnd,
+			newAllDay,
+			dateDelta,
+			durationDelta
+		);
+	}
+
+
+	// Modifies an array of events in the following ways (operations are in order):
+	// - clear the event's `end`
+	// - convert the event to allDay
+	// - add `dateDelta` to the start and end
+	// - add `durationDelta` to the event's duration
+	//
+	// Returns a function that can be called to undo all the operations.
+	//
+	function mutateEvents(events, clearEnd, forceAllDay, dateDelta, durationDelta) {
+		var isAmbigTimezone = t.getIsAmbigTimezone();
+		var undoFunctions = [];
+
+		$.each(events, function(i, event) {
+			var oldAllDay = event._allDay;
+			var oldStart = event._start;
+			var oldEnd = event._end;
+			var newAllDay = forceAllDay != null ? forceAllDay : oldAllDay;
+			var newStart = oldStart.clone();
+			var newEnd = (!clearEnd && oldEnd) ? oldEnd.clone() : null;
+
+			// NOTE: this function is responsible for transforming `newStart` and `newEnd`,
+			// which were initialized to the OLD values first. `newEnd` may be null.
+
+			// normlize newStart/newEnd to be consistent with newAllDay
+			if (newAllDay) {
+				newStart.stripTime();
+				if (newEnd) {
+					newEnd.stripTime();
+				}
+			}
+			else {
+				if (!newStart.hasTime()) {
+					newStart = t.rezoneDate(newStart);
+				}
+				if (newEnd && !newEnd.hasTime()) {
+					newEnd = t.rezoneDate(newEnd);
+				}
+			}
+
+			// ensure we have an end date if necessary
+			if (!newEnd && (options.forceEventDuration || +durationDelta)) {
+				newEnd = t.getDefaultEventEnd(newAllDay, newStart);
+			}
+
+			// translate the dates
+			newStart.add(dateDelta);
+			if (newEnd) {
+				newEnd.add(dateDelta).add(durationDelta);
+			}
+
+			// if the dates have changed, and we know it is impossible to recompute the
+			// timezone offsets, strip the zone.
+			if (isAmbigTimezone) {
+				if (+dateDelta) {
+					newStart.stripZone();
+				}
+				if (newEnd && (+dateDelta || +durationDelta)) {
+					newEnd.stripZone();
+				}
+			}
+
+			event.allDay = newAllDay;
+			event.start = newStart;
+			event.end = newEnd;
+			backupEventDates(event);
+
+			undoFunctions.push(function() {
+				event.allDay = oldAllDay;
+				event.start = oldStart;
+				event.end = oldEnd;
+				backupEventDates(event);
+			});
+		});
+
+		return function() {
+			for (var i=0; i<undoFunctions.length; i++) {
+				undoFunctions[i]();
+			}
+		};
+	}