Fixes#9905
This fixes a major compatibility issues with the CSI S sequence:
When our top margin is at the top (row 0) without left/right
margins, we should be creating scrollback. Previously, we were
only deleting.
This improves the `clearCells` function since it only has to update once
after clearing all of the individual cells, or not at all if the whole
row was cleared since then it knows for sure that it cleared them all.
This also makes it so that the row style flag is properly tracked when
cells are cleared but not the whole row.
This fixes the VS16 issues found in this test:
https://ucs-detect.readthedocs.io/sw_results/ghostty.html#ghostty
This is also a more robust way to handle VS15/16 in general.
This commit also changes our propeties to be a packed struct which
reduces its size from 4 bytes to 1 and likewise drops our unicode table
size 4x.
This updates uucode. As part of this, the wcwidth implementation was
updated (in uucode) to make emoji modifiers width ZERO. But if they're
standalone, we want them as width 2.
So this also contains a change to force them as width 2 for our width
calculation. This only matters for standalone emoji modifiers, because
when they form a valid grapheme we don't use this width calculation.
This adds a new stream handler implementation that updates terminal
state in reaction to VT sequences, but doesn't perform any of the
actions that would require responses (e.g. queries).
This is exposed in two ways: first, as a standalone `ReadonlyStream` and
`ReadonlyHandler` type that contains all the implementation. Second, as
a convenience func on `Terminal` as `vtStream` and `vtHandler` which
return their respective types preconfigured to update the calling
terminal state.
This dramatically simplifies libghostty-vt usage from Zig (and will
eventually be exposed to C, too) since a Terminal on its own is ready to
go as a full VT parser and state machine without needing to build any
custom types!
There's a second big bonus here which is that our `stream_readonly.zig`
tests are true end-to-end tests for raw bytes to terminal state. This
will let us test a wider variety of situations more broadly. To start,
there are only a handful of tests implemented here.
**AI disclosure:** Amp wrote basically this whole thing, but I reviewed
it. https://ampcode.com/threads/T-3490efd2-1137-4112-96f6-4bf8a0141ff5
This makes it cleaner to add new sources of table generation and also
avoids inadvertently depending on different modules (despite Zig's lazy
analysis).
This also fixes up terminal to only use our look up tables which avoids
bringing ziglyph in for the terminal module.
Without this change, a phantom space appears after any character with
default emoji presentation that is converted to text with VS15. The only
other terminal I know of that respects variation selectors is Kitty, and
it walks the cursor back, which feels like the best choice, since that
way the behavior is observable (no way to know if the terminal supports
variation selectors otherwise without hard-coding that info per term)
and "dumb" programs like `cat` will output things correctly, and not
gain a phantom space after any VS15'd emoji.
This brings the behavior of mode 47, 1047, and 1049 much closer to
xterm's behavior. I found that our prior implementation had many
deficiencies.
For example, we weren't properly copying the cursor state back to the
primary screen from the alternate screen for modes 47 and 1047. And we
weren't saving/restoring cursor state unconditionally for mode 1049 even
if we were already in the alternate screen.
These are weird, edgy behaviors that I don't think anyone expected
(evidence by there being no bug reports about them), but they are bugs
nontheless.
Many tests added.
As of Zig 0.14.0, `@splat` can be used for array types, which eliminates
a lot of redundant syntax and makes things generally cleaner.
I've explicitly avoided applying this change in the renderer files for
now since it would just create rebasing conflicts in my renderer rework
branch which I'll be PR-ing pretty soon.
