Fixes#1183
I'm not sure why the original logic was there. When I translated the
original test cases to shell and ran them in xterm, they did NOT match
what Ghostty expected. This updates the tests to match xterm and removes
this case. We can add back in more tests if/when we figure out under
what scenario this original logic was correct (if it ever was).
This adds a new configuration `grapheme-width-method` to change the
default behavior that Ghostty uses to calculate grapheme width. The
default value is `unicode` which is identical to setting mode 2027.
**IMPORTANT:** This changes the default Ghostty behavior to be fully
grapheme-aware including ZWJs, VS15, VS16. This may cause issues with
some legacy programs and shells.
I've changed my mind that this should become the default because enough
people use emojis now that I've found in the beta program there are more
issues reported about "incorrect emoji width" than any possibly desync
issues. We'll see.
For legacy programs, this can still be set to `grapheme-width-method =
wcswidth`.
Only SGR, DECSCUSR, DECSTBM, and DECSLRM are handled, as these are the
only ones that Ghostty supports (as far as I can tell) and are the only
ones that seem actually useful.
Use the .text field of the enum as the default value of the mouse shape
instead of renaming .default. Store the default value as the current
value for use in subsequent commits
Fixes a crash found through fuzzing. This crash is also exhibited in
xterm (as of v384). The issue arises when you set the cursor above the top
scroll margin, then issue a large cursor left (CSI D) with extended reverse
wrap (?1045) set. Extended reverse wrap loops back until it reaches the top
scroll then wraps around. But since the cursor is before the top scroll,
xterm just arbitrarily moves back into negative row numbers, which reads into
bad memory.
We decided to fix this by clamping to (0,0) and exiting because this
will mimic the xterm behavior for valid values of cursor left count
(prior to crashing).
