Balloon panel doesn't show up after click when link is not highlighted

[oskarwrobel]

[szymonkups]

I've tested this a little and it looks like this is because highlight's <span> element is created on top of <a> element. The failing flow is like this:

1. User clicks on a link,
2. selectionchange event is fired before click event, it triggers changes on the model,
3. Postfixer is adding marker over link,
4. Marker is rendered as <span> over <a> element and Renderer is creating brand new <a> in the DOM,
5. No click event since old <a> is removed from DOM.

We will fix this by adding highlight with higher priority than link one, so the <span> will be rendered inside <a> element.

[Reinmar]

The PR proposed by @szymonkups in ckeditor/ckeditor5-link#179 was a workaround which changed how the highlight is rendered. From:

<span class=highlight><a href=#>xxx</a></span>

To:

<a href=#><span class=highlight>xxx</span></a>

It fixes this issue in Chrome, but:

• it's still broken in Firefox and Safari,
• new issues appear.

However, most importantly, it's still wrong – the highlight must not be rendered as a separate span. It should be a class on the original <a> element. Toggling a class will be much safer than changing the DOM structure.

Unfortunately, switching to a class-based highlight is blocked now by a much bigger issue. Therefore, we won't manage to fix this issue before releasing beta.1.

So, I think that we should still go with the highlight on and live with this bug for a while. It definitely needs to be fixed before the first stable release and it's definitely quite critical. However, we also need to be able to see how the link highlight feature behaves – it's better not to add it like that in a final release.