False in event data is incorrectly handled as an event cancellation

[Comandeer]

Type of report

Bug

Provide detailed reproduction steps (if any)

1. Open console.
2. Go to https://jsfiddle.net/Comandeer/xc3jqt6n/
3. Look into the console.

Expected result

Both 1 and 2 are logged.

Actual result

Only 1 is logged.

Other details

• CKEditor version: 4.5.0+

It seems that false passed as event data is treated the same way as the marker of event cancellation (

ckeditor4/core/event.js

Lines 310 to 318 in 2ed7789

	if ( retData === false )
	canceled = 1;
	else if ( typeof retData != 'undefined' )
	data = retData;
	// No further calls is stopped or canceled.
	if ( stopped || canceled )
	break;
	}

). The issue seems to be easily fixable by introducing event cancellation marker (just an empty object), which will be returned instead of false in case of event cancellation. Thanks to properties of object (they equal only themselves), we will be able to differentiate between cancelling events and event data set to false.

[CKEditorBot]

Closed in #4656