Revert "Merge branch 't/13798'"

This reverts commit 8565201, reversing
changes made to e4f2432.

CHANGES.md

@@ -21,7 +21,6 @@ Fixed Issues:
 * [#12848](http://dev.ckeditor.com/ticket/12848): [Blink] Fixed: Opening the [Find and Replace](http://ckeditor.com/addon/find) dialog window in the [read-only](http://docs.ckeditor.com/#!/api/CKEDITOR.editor-property-readOnly) mode throws an exception.
 * [#13879](http://dev.ckeditor.com/ticket/13879): Fixed: It is not possible to prevent the [`editor.drop`](http://docs.ckeditor.com/#!/api/CKEDITOR.editor-event-drop) event.
 * [#13361](http://dev.ckeditor.com/ticket/13361): Fixed: Skin images fail when the site path includes parentheses because the `background-image` path needs single quotes around the URL value.
-* [#13798](http://dev.ckeditor.com/ticket/13798): [Firefox] Fixed: Changing paragraph format causes the cursor to move.
 * [#13771](http://dev.ckeditor.com/ticket/13771): Fixed: The `contents.css` style is not used if the [IFrame Editing Area](http://ckeditor.com/addon/wysiwygarea) plugin is missing.
 * [#13782](http://dev.ckeditor.com/ticket/13782): Fixed: Unclear log messages.
 * [#13919](http://dev.ckeditor.com/ticket/13919): [Edge] Fixed: Browser window crashes when accessing the `isContentEditable` property of an `<input>` DOM element.

core/editable.js

@@ -1108,9 +1108,9 @@
 					} );
 				}
 
-				// Prevent Webkit/Blink/Gecko from going rogue when joining
-				// blocks on BACKSPACE/DEL (#13798,#11861,#9998).
-				if ( CKEDITOR.env.webkit || CKEDITOR.env.gecko ) {
+				// Prevent Webkit/Blink from going rogue when joining
+				// blocks on BACKSPACE/DEL (#11861,#9998).
+				if ( CKEDITOR.env.webkit ) {
 					this.attachListener( editor, 'key', function( evt ) {
 						if ( editor.readOnly ) {
 							return true;

tests/core/editable/keystrokes/keystrokes.js

@@ -166,13 +166,5 @@ bender.test( {
 		// No content in a parent list.
 		this.assertKeystroke( DEL, 0, '<ul><li><table><tbody><tr><td>[foo]</td></tr></tbody></table></li></ul>',
 			'^', 'table 3' );
-	},
-
-	// ##13798
-	'test caret position after pressing BACKSPACE between blocks in Firefox': function() {
-		if ( !CKEDITOR.env.gecko )
-			assert.ignore();
-
-		this.assertKeystroke( BACKSPACE, 0, '<h1>Head</h1><p>^ing</p>', '<h1>Head^ing</h1>', 'blocks are correctly joined' );
 	}
-} );
+} );