@eht16 and @elextr
As I mentioned above in comment https://github.com/geany/geany/issues/3271#issuecomment-1236986241, there are three different issues: short lines, last lines of paragraphs and lines that are going till the right border.
For the lines that are going till the right border I opened already at sourceforge a new bug, because in the moment where buffered drawing (SCI_SETBUFFEREDDRAW) is turned off, there is an empty line and there is still a problem with the keyboard-navigation (https://sourceforge.net/p/scintilla/bugs/2349/#b6c6).
For short lines and last lines of paragraphs, I would like to open a new bug at sourceforge by mentioning those facts: - When buffered drawing (SCI_SETBUFFEREDDRAW) is turned on, then the issue occurs on the geany-git by PPA that was built about 16 days ago (https://github.com/xiota/geany/issues/2#issuecomment-1236227970) on two different computers five days ago (https://github.com/xiota/geany/issues/2#issuecomment-1248033244), on a 15.6´´-FHD-notebook and standalone PC connected to a 22´-display. - When buffered drawing (SCI_SETBUFFEREDDRAW) is turned off on the geany-git by PPA that was built about four days ago (https://github.com/xiota/geany/issues/2#issuecomment-1248808860), then the issue does not appear any more (https://github.com/xiota/geany/issues/2#issuecomment-1249414773 and https://github.com/xiota/geany/issues/2#issuecomment-1249501316).
Because of that: Is it OK if I ask at sourceforge to turn off buffered drawing (SCI_SETBUFFEREDDRAW) by default?