Basic style cannot be re-applied

[Tobiasz Cudnik]

Basic style cannot be re-applied, a regression since 3.4.1.

1. Use a following content:

   <p>
   	<strong>this [is</strong> some] sample text</p>
   

2. Press the Bold button, to remove a bold style.
3. Press the Bold button again, to apply it on the selection.

Expected: The bold text is "this is some".

Result: The bold text is "this".

Relevant UnitTest: test_inline14

[Paweł Horzela]

The issue was introduced in [5994].

[Sa'ar Zac Elias]

Using the same TC and trying to remove the newly created element doesn't work. This is caused by the change of L888.

[Garry Yao]

Nice catch.

[Garry Yao]

Fixed with [6030].