Scrollbar in drop-down list disappears after initial display

[Yanual]

Issue is already reported on old issue tracking

see https://dev.ckeditor.com/ticket/14716

Reproduction steps

1. Go to https://ckeditor.com/ckeditor-4 with chrome browser
2. Click on the Styles drop-down in the Toolbar so the list of styles is displayed
3. Click away so the list of styles is hidden
4. Click on the Styles drop-down a second time - notice that when the list of styles is re-displayed the vertical scrollbar is now missing.

Expected result

Display Scrollbar each time the list is displayed

Actual result

After initial display the Scrollbar disappears

Other details

• Browser: Chrome 62.0.3202.75
• CKEditor version: 4.8.1

Additional Informations

This seems to be a chromium issue, see https://bugs.chromium.org/p/chromium/issues/detail?id=641881

Possible solution

For me the problem appears with the list of font sizes (I do not use styles and formats, incompatible with BBCode).
I made a change in panel / plugin.js on line 370 that works without disrupting the online menus and the color list.
Replace the code in line 370 (4.8.1 version) with this one :

// To avoid Chrome issue see https://bugs.chromium.org/p/chromium/issues/detail?id=641881
if ( CKEDITOR.env.chrome && this.attributes.role == 'listbox' && this.element.$.className == 'cke_panel_block' ) {
	this.element.setStyle( 'display', 'inline' );
} else {
	this.element.setStyle( 'display', '' );
}

Could you tell me if this is not awkward for other uses of CKEditor and if so it may help other people ?

[msamsel]

I was able to confirm the issue.

[mlewand]

@Yanual as you mentioned this is an upstream issue, and all we can do is hack to get a way around it. Please bump the original chromium issue (star it and/or put a comment) so that they see some interest in this issue.

[Yanual]

I just did it and I asked them why the status of the issue remains WontFix

[mlewand]

They claimed that's no longer reproducible:

No longer reproduces in 60 or later.

That's why, though my bet is that the tester had used wrong environment where it's not reproducible. AFAIR it's not reproducible on mac.

[Yanual]

Like I said I reproduce it on Browser: Chrome 62.0.3202.75 and on comment #16 he said -> I can confirm this issue happening in Windows and Linux in Chrome 63. It doesn't happen in MacOS with the "always show scrollbars" setting on.
That's why I'm perplexed about their analysis of feedback.

[mlewand]

It looks like it's fixed on Chrome 65. We can already close this issue as it's an upstream. I'm happy to see it's fixed though. Version 65 is estimated to get stable at the beginning of March, so let's keep an eye on that.

[williamsherlock]

This solution work for me:
Go to the ckeditor.js into callFunction and add this line before return.

$(".cke_combopanel").css("width", 'auto');