1921929 - Make `HTMLEditor` stop deleting inline elements when they become empty as far as possible especially in `contenteditable=plaintext-only`

Status: NEW

(Core :: DOM: Editor, enhancement)

Description

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

New tests which will be added in bug 1921723 won't pass on Firefox and Chrome in the following case and similar cases.

<p><b>[a]</b></p>

Delete the selection, then, the DOM becomes:

<p><br></p>

So, <b> is deleted. However, the builtin editors cache the bold style. Therefore, when you type "c", then, <b> is restored.

<p><b>c</b><br></p>

However, the <br> is put stays outside of the <b>. Additionally, if you type "c" after moving caret, the cache may be discarded. Then, you'll see

<p>c<br></p>

In contenteditable=plaintext-only, document.execCommand("bold") does not work. So, even the web app cannot restore the bold style with keeping the undo transactions.

So, I think that when the paragraph becomes empty, the DOM should become:

<p><b><br></b></p>

Then, typing new character at the <br> will be in <b> consistently.

Comment 1

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Unfortunately, our HTMLEditor puts the <br> for empty paragraph in OnEndHandlingTopLevelEditSubActionInternal() (by AdjustCaretPositionAndEnsurePaddingBRElement) after removing the <b> (by RemoveEmptyNodesIn). So perhaps, we need to make the delete handlers put <br> elements before OnEndHandlingTopLevelEditSubActionInternal runs.