Description:
When pasting text from a text editor into a text box in Impress, local formatting gets incorrectly propagated. 

Steps to Reproduce:
1. Create a new Impress document
2. Remove the default text boxes. 
3. Create a new blank textbox using F2 and dragging a box.
4. Type ctrl-B (bold) then "Hello", then ctrl-B (un-bold) and "Here is some text. "
5. Go to your text editor and type "Something from my text editor". Copy the text and return to LibreOffice. Double-click the text box, place the cursor at the end of the text, and press ctrl-V (paste).


Actual Results:
Upon pasting, the entire text box including pasted text becomes bold. It appears that some logic is being applied to pick up the formatting of the first character in the text box, and applying it to the entire thing, instead of picking up the formatting of the last character (or the current settings where the cursor is, more precisely) and applying it to just the pasted text.

Expected Results:
Clearly the "Here is some text. " as well as the "Something from my text editor" should both be un-bold.


Reproducible: Always


User Profile Reset: No

Additional Info:
Version: 7.6.7.2 (X86_64) / LibreOffice Community
Build ID: 60(Build:2)
CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3
Locale: en-AU (en_AU.UTF-8); UI: en-US
Ubuntu package version: 4:7.6.7-0ubuntu0.20.04.1~lo1
Calc: threaded