Intentional deviation from Ghostty 1.3.1 (upstream data-loss bugs, see
docs/rewrite/DEVIANT_FIXES.md and docs/rewrite/notes/final-Z17.md):
- Zig 0.15's File.writer writes positionally (pwrite) at each writer's
own offset, starting at 0, while the file is seekable. When stdout is
a regular file, two writers (e.g. +show-face) overwrite each other and
any existing content, and File.Writer.end truncates. ZigWriter always
appends at the current end and end() only flushes.
- Writers that are never flushed lose their buffered output in Zig, e.g.
+list-themes' stderr buffer, so "No themes found..." is never printed.
ZigWriter flushes on drop.
Zig's buffering and flush order (and thus pipe/tty interleaving) is kept
unchanged; only the data loss is not replicated.
Test Plan:
- cargo test -p ghostty-cli zig_writer
(regular_file_output_is_complete_and_appended,
unflushed_buffer_is_flushed_on_drop)
- ghostty +list-themes with a missing resources dir prints the message
