Switching buffers between files differing in number of lines does not maintain scroll position
I discovered what the ‘bitmap of logical drives’ is for, by the way. It is only relevant when the protected-mode DriveSpace driver is loaded; one bit is set for each drive letter corresponding to a mounted compressed volume hosted on the given drive. Since FreeDOS doesn’t do drive compression, returning zero here should be fine. On the other hand, if DriveSpace somehow were installed under FreeDOS…
Taking your time, I suppose…
The problem reproduces for all characters when I set font.base=font:DejaVu Sans or font.base=font:DejaVu Serif. It appears as if for some inexplicable reason Scintilla renders the buffer in DejaVu Sans/Serif Condensed, but the font metric calculations use the regular DejaVu Sans/Serif. Likewise for a number of other fonts with a Condensed variant, but not for Roboto. When I actually choose the Condensed variant, the problem disappears. libpangocairo 1.50.3+ds1-6, fontconfig 2.13.1-4.4, libfreetype6...
The problem reproduces for all characters when I set font.base=font:DejaVu Sans or font.base=font:DejaVu Serif. It appears as if for some inexplicable reason Scintilla renders the buffer in DejaVu Sans/Serif Condensed, but the font metric calculations use the regular DejaVu Sans/Serif. Likewise for a number of other fonts with a Condensed variant, but not for Roboto. libpangocairo 1.50.3+ds1-6, fontconfig 2.13.1-4.4, libfreetype6 2.11.1+dfsg-1, libharfbuzz0b 2.7.4-1 (Debian testing)
More screenshots with ‘≺’
The problem reproduces for all characters when I set font.base=font:DejaVu Sans or font.base=font:DejaVu Serif. It appears as if for some inexplicable reason Scintilla renders the buffer in DejaVu Sans/Serif Condensed, but the font metric calculations use the regular DejaVu Sans/Serif. Likewise for a number of other fonts with a Condensed variant, but not for Roboto. libpangocairo 1.50.3+ds1-6, fontconfig 2.13.1-4.4, libfreetype6 2.11.1+dfsg-1, libharfbuzz0b 2.7.4-1 (Debian testing)
Character positions are miscomputed in the presence of glyphs missing from the selected font