Created attachment 52518 [details]
3 screen captures of the problem occurring in different locations.
(To start, I don't know if this is the right area to submit this bug - I read the list and picked as best as I could. Sorry, new to the LO project)
It appears that in my version (3.4.3 OOO340m1 (Build:302) ) my characters are frequently overlapping. As I type a line the characters on that line frequently (once every 10-15 lines) become muddled together. It seems to have something to do with the spacing between characters and words changing - the "old" character positions don't get cleared before the new characters are drawn. If I switch application focus out of LO and then back, the problem is gone and all characters are clean. If I scroll up and down, leaving the muddled bit visible in the document, then there is no effect. If I scroll the document beyond the muddled characters and then return to where I started, then all characters are clean. If I select the muddled characters there is no effect.
Some pictures showing this are attached.
Moving to product LibreOffice since this isn't about the DejaVu fonts.
Can you still reproduce the issue with the latest version of LibreOffice?
Cannot replicate, please close