Bug 38703 – user-select none should not clear selection

• Component: HTML Editing
• Status: NEW

[Erik Arvidsson]

Created attachment 55315 [details]
Test 

If I have some selected text and then do a mousedown on an element that has user-select none the current selection should not be cleared.

The code to fix this is in Node::canStartSelection.

if (style->userDrag() == DRAG_ELEMENT && style->userSelect() == SELECT_NONE)

should be changed to

if (style->userDrag() == DRAG_ELEMENT || style->userSelect() == SELECT_NONE)

The following two LayoutTests needs to be updated as well:

editing/selection/5333725.html
editing/selection/user-drag-element-and-user-select-none.html

Does this need #if ENABLE(DRAG_SUPPORT) flags as well? It will probably work fine without with the proposed change but all other uses of userDrag() have the define wrapped around it somewhere.

[Neil Ashford]

Created attachment 419682 [details]
An extra HTML file with a similar (possibly the same) issue

The same issue, but specifically where the first selection is in a content editable element, is affecting my product. I'm using Safari 14.0.2 on MacOS 11.1, so it looks like this bug (or some variant of it) is still happening.

[Caleb Hearon]

Based on the "Test" attachment, the original bug looks fixed: clicking on `-webkit-user-select: none` doesn't destroy text selection. But like Neil said, it _does_ destroy selection if the selection is in [contentEditable].

This makes it really difficult to support Safari if you have a WYSIWYG editor and have div-based controls that operate on the selection. You want the selection to stay the same while the user formats it.

Oddly the native <button> passes the test cases in both attachments.