As discussed at length in issue #182, the existing pdf.ttf causes difficulties
for certain PDF viewers, in part because the old file had zero advance width.
With testing, sharp2.ttf seems to be the best available compromise, although
it's not perfect and causes some visual difficulties in Evince. It does
seem to fix Kindle and OS X Preview.
to improve correctness and compatibility with
external programs, particularly ghostscript.
We will start mapping everything to a single glyph,
rather than allowing characters to run off the end
of the font.
A more detailed design discussion is embedded into
pdfrenderer.cpp comments. The font, source code
that produces the font, and the design comments
were contributed by Ken Sharp from Artifex Software.