Description:
If a word or phrase is highlighted in Impress then when it writes to a pptx file it extends this highlight to the end of line or to the next highlight.
Also, When Impress reads a pptx document written by Powerpoint it extends the text highlights to the end of line in a similar manner

Steps to Reproduce:
1.Key in some text to an impress slide. then highlight a word
2.save file as pptx
3.read file in again in Impress and examine the highlight

Actual Results:
Key in "This is some text"
Highlight "some"
save to pptx
when read back in "some text" is highlighted

Expected Results:
only "some" should be highlighted


Reproducible: Always


User Profile Reset: Yes



Additional Info:
When this is tested it needs to be tested on inputs from Powerpoint as well, reading and writing files in both Impresse and Powerpoint, passing files through 2-3 interations between them.

I am running Libreoffice version 7.0.1.2 on both Windows and Linux (Fedora 32 and Debian 10) and the problem is the same on both