[Chrome] Error thrown when destroying focused inline editor

[lb009]

Steps to reproduce

1. Focus is on the editor, not blur
2. Click jQuery UI Dialog cancel button ,then fire close event:

      close: function () 
      {
          editor.destroy();
          editor = null;
      }
   

3. Uncaught TypeError: Cannot read property 'isInline' of null

at CKEDITOR.focusManager.d (ckeditor.js:238)

at CKEDITOR.focusManager.<anonymous> (ckeditor.js:238)

at ckeditor.js:28

Actual result

After call editor.destroy(),editor.editable() return null

// Blink browsers leave selection in `[contenteditable=true]`
// when it's blurred and it's neccessary to remove it manually for inline editor. (#13446)

if ( CKEDITOR.env.chrome && editor.editable().isInline() ) {
editor.window.$.getSelection().removeAllRanges();
}

Other details (browser, OS, CKEditor version, installed plugins)

Chrome 55.0.2883.87 m

CKEditor 4.6.2

[Jakub Ś]

Problem can be reproduced from CKEditor 4.6.2 in Chrome only.

[Denis]

Illustrate focusManager trying to blur a destroyed editor

[Denis]

Got the same bug. Here are possible reason and solution, and also a workaround.

The Focus Manager focus and blur editors "asynchronously" with some delay. When destroying a CKEditor with focus, this result in an attempt to blur a released editor and produce an exception.

Steps to Reproduce

0. Use a blink browser (Chrome or Opera).
1. See this demo: ​https://jsfiddle.net/rbo0o8ze/, or download attachment (bug_focusManager.html).
2. Once editor loaded and focused click "delete".
3. See error in console.

Actual Result

Exception is thrown:

Uncaught TypeError: Cannot read property 'isInline' of null
    at CKEDITOR.focusManager.doBlur (focusmanager.js:161)
    at CKEDITOR.focusManager.<anonymous> (focusmanager.js:180)
    at tools.js:578

Expected Result

Don't throw...

Workaround

Problem can be avoid by forcing the editor to blur without delay before destroy: editor.focusManager.blur(true). See "Steps to Reproduce" demo.

Bug Reason

Error is caused in doBlur function contained in blur method of focusManager. See: ​https://github.com/ckeditor/ckeditor-dev/blob/2db0ce3e25f9c97404e2be107e1250a78254ddd7/core/focusmanager.js#L161-L163.

When the editor is destroyed, editor.editable() is set to null. See ​https://github.com/ckeditor/ckeditor-dev/blob/2db0ce3e25f9c97404e2be107e1250a78254ddd7/core/editor.js#L807.

Hence, editor.editable().isInline() can only fail.

The CKEDITOR.env.chrome test explains why this only occurs on blink browsers.

Proposed Solution

I propose to make a pull request changing the line:

if ( CKEDITOR.env.chrome && editor.editable().isInline() ) {

by

if ( CKEDITOR.env.chrome && editor.editable() && editor.editable().isInline() ) {

This make the code work as expected.

[Tade0]

Indeed this check was missing. Thank you, denisname.

Added a unit test for this case. Changes pushed to ​branch:t/16825.

[Marek Lewandowski]

• Given unit test doesn't test this bug. When checked out major version of core\focusmanager.js, test still passes.
• I'm also missing manual test.

I have rebased the branch to the latest major.

[Tade0]

Updated unit test, added manual test, rebased with major.

Changes pushed to ​branch:t/16825.

[Marek Lewandowski]

For reference, first bad commit was ​git:2c0d9802bd809bb3c28c86ea8ff911f351d6ae18.

[Marek Lewandowski]

Added some changes, mainly to tests.

Fixed with ​git:33bd6288af, merged to major.