The fonts set in setoptions aren't consistently picked up by ttk, which
uses its own predefined fonts. This is noticeable when switching
between using and not using ttk with custom fonts or in HiDPI settings
(where the default TTK fonts do _not_ respect tk sclaing).
Fix by mapping the ttk fontset to the one used by gitk internally.
Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com> Signed-off-by: Paul Mackerras <paulus@samba.org>