Ghostty previously incorrectly only created scrollback if the top/bot
margins were the full height of the viewport. The actual xterm behavior
is to create scrollback as long as the top margin is the top row and the
cursor is on the bottom margin (wherever that may be).
Kitty 0.36.0 added support for a new OSC escape sequence for
quering, setting, and resetting the terminal colors. Details
can be found [here](https://sw.kovidgoyal.net/kitty/color-stack/#setting-and-querying-colors).
This fully parses the OSC 21 escape sequences, but only supports
actually querying and changing the foreground color, the background
color, and the cursor color because that's what Ghostty currently
supports. Adding support for the other settings that Kitty supports
changing ranges from easy (cursor text) to difficult (visual bell,
second transparent background color).
Before this fix, if vsync was on the GPU cells buffer could be cleared
for a frame while resizing the terminal down. This was due to the fact
that the surface sent messages for the resize to both the renderer and
the IO thread. If the renderer thread was processed first then the GPU
cells buffer(s) would be cleared and not rebuilt, because the terminal
state would be larger than the GPU cell buffers causing updateFrame to
bail out early, leaving empty cell buffers.
This fixes the problem by changing the origin of the renderer's resize
message to be the IO thread, only after properly updating the terminal
state, to avoid clearing the GPU cells buffers at a time they can't be
successfully rebuilt.
Fixes#2081
Many fonts have a bad ligature for "fl", "fi", or "st". We previously
maintained a list of such fonts in quirks.zig. However, these are so
common that it was suggested we do something more systematic and this
commit is that.
This commit changes our text run splitting algorithm to always split on
`fl`, `fi`, and `st`. This will cause some more runs for well behaved
fonts but the combination of those characters is rare enough and our
caching algorithm is good enough that it should be minimal overhead.
This commit renders our existing quirks fonts obsolete but I kept that
logic around so we can add to it if/when we find other quirky font
behaviors.
