Merge pull request #4800 from ckeditor/t/4782

Prevent autocomplete invocation on not existing editable [FF]

CHANGES.md

@@ -15,6 +15,7 @@ Fixed Issues:
 * [#3638](https://github.com/ckeditor/ckeditor4/issues/3638): Fixed: Opening the same dialog twice causes it to become hidden under the dialog's page cover.
 * [#4247](https://github.com/ckeditor/ckeditor4/issues/4247): Fixed: [Color Button](https://ckeditor.com/cke4/addon/colorbutton)'s incorrect rendering on the first opening.
 * [#4555](https://github.com/ckeditor/ckeditor4/issues/4555): Fixed: [Font](https://ckeditor.com/cke4/addon/font) styles with attributes are not applied correctly when used multiple times over the same selection.
+* [#4782](https://github.com/ckeditor/ckeditor4/issues/4782): [Firefox] Fixed: `TypeError` is thrown when switching to Source View and back while [Autocomplete](https://ckeditor.com/cke4/addon/autocomplete) plugin is enabled.
 
 ## CKEditor 4.16.1
 

plugins/autocomplete/plugin.js

@@ -347,7 +347,7 @@
 			var editable = this.editor.editable(),
 				isActive = evt.data;
 
-			if ( !editable.isInline() ) {
+			if ( !editable || !editable.isInline() ) {
 				return;
 			}
 

tests/plugins/emoji/manual/editablenullerror.html

@@ -0,0 +1,9 @@
+<textarea id="editor"></textarea>
+
+<script>
+	if ( bender.tools.env.mobile ) {
+		bender.ignore();
+	}
+
+	CKEDITOR.replace( 'editor' );
+</script>

tests/plugins/emoji/manual/editablenullerror.md

@@ -0,0 +1,9 @@
+@bender-tags: 4.16.2, bug, emoji, 4782
+@bender-ckeditor-plugins: wysiwygarea, sourcearea, toolbar, emoji 
+@bender-ui: collapsed
+
+1. Open browser's dev console.
+1. Switch to `source` mode.
+1. Switch to `wysiwyg` mode.
+
+**Expected** No errors in the console.