Editor viewport is scrolled back to the top when focusing editor for the first time

[jbalsas]

Are you reporting a feature or a bug?

Bug

Original Report (14827)

Provide detailed reproduction steps (if any)

In Microsoft Edge 14

1. Go to http://ckeditor.com/demo.
2. Scroll editor viewport without focusing editor (e.g. using mouse wheel).
3. Click inside editor content to focus editor.

Optionally, simply do:

1. Go to http://ckeditor.com/demo
2. Click on the word oven inside the editor

This can also be reproduced in nightly.ckeditor.com

Expected result

The cursor to be placed where the mouse was pressed (the oven word) and the scroll position of the editor (if any) to be preserved

Actual result

The cursor is placed at the beginning of the content and the scroll position (if any) is lost

Other details

• Browser: Microsoft Edge 14
• OS: Windows 10
• CKEditor version: CKEditor 4.7
• Installed CKEditor plugins: default ones in CKEditor's demo

[jbalsas]

Hey @jswiderski, could we also label this as a bug, or are there some specific rules for that that this issue doesn't cover?

[Comandeer]

After some investigation, it seems that the source of issue is located in core/editable.js, in – ironically – function called fixDom → https://github.com/ckeditor/ckeditor-dev/blob/eb4a25a16a6b0241d655f6a94af5d1568c9f2d9f/core/editable.js#L1428

This function is called on every editor's selectionChange event. This event is also fired on every editor's focus via https://github.com/ckeditor/ckeditor-dev/blob/eb4a25a16a6b0241d655f6a94af5d1568c9f2d9f/core/selection.js#L938-L941

The issue appears because Edge reports the click into editable as range collapsed to the beginning of the editor and fixDom treats this as selection neeeded update, reselecting this range. Chrome also reports such range for the click, however fixDom treats it as correct selection and does not do reselection.