Font color will not be inherited if the text is typed in between two lines of text

[giorgio]

1. Open the nightly version of ckeditor
2. Navigate to "Text Color" and select "Red"
3. Enter text into the editor
4. Hit Enter and then type some more text on the next line
5. Hit Enter, then hit enter again (so there is a empty line)
6. Type in some text
7. Click on (or arrow up to) the empty line above the text you just entered and enter some text

Bug: the text on line 1, 2, and 4 are red as expected, but the text on line 3 is black.

The html reveals that when the empty line is clicked and text is entered it is placed outside the span with the font styles (see text in bold below).

<p>

<span style="color:#FF0000;">red text</span> <br>

</p> <p>

<span style="color:#FF0000;">red text</span> <br type="_moz">

</p> <p>

<span style="color:#FF0000;"></span>red <br type="_moz">

</p> <p>

<span style="color:#FF0000;">red text</span> <br type="_moz">

</p>  

[Jakub Ś]

DUP of #12634.