All three were review findings, and all three shared a shape: the code
that decided a mode and the thing that held it were allowed to differ.
The GPU compared against a shadow field. code_wrap started at
Wrap::None while the cosmic-text buffer had never had set_wrap called
at all, so it was still on the constructor default WordOrGlyph. Since
apply_line_wrap short-circuits when the request already matches, the
FIRST wrap: false was a no-op and the document kept word wrapping. The
existing test hid it by sending true first, which synced the buffer as
a side effect.
Fixed twice over. The document buffer now declares its wrap at
construction like every other buffer in the file --- Wrap::Glyph, not
None, because ui.line-wrap defaults to wrap, so a frontend told nothing
(or talking to a pre-v22 daemon that never will tell it) should already
be in the default mode. And the shadow field is GONE: apply_line_wrap
reads self.buffer.wrap() instead. A cached copy can disagree with the
authority; reading the authority cannot. Same principle as byte
anchoring and the fold-projection cache key.
The first attempt at that fix set Wrap::None at construction, which
made truncate the pre-message default and broke eleven tests --- the
GPU had always wrapped, and the setting's default is wrap. The failures
were right and the change was wrong.
A one-column viewport shoved every wide glyph down a row. The rule
moves a double-width glyph to the next row when it will not fit in the
cells left, but at one column it will not fit there either --- so a
single CJK character rendered on row 1 with row 0 left blank, and
clipped anyway. Now it only moves when the next row could actually hold
it (max_cols >= 2); below that it clips in place, which is what
Truncate does at the edge for exactly the same reason.
A zero-column content area panicked. Under Wrap the first
col >= max_cols test is true immediately, so the walk advanced a row
and then indexed column 0 of a zero-width grid. Reachable whenever the
gutter consumes the window's width. paint_line now returns before the
walk, and put() refuses out-of-range columns as a second line.
Four witnesses, all biting. The GPU one took three attempts to make
discriminating: wrap-versus-truncate could not see the bug (both modes
differ from each other either way), and a row-count comparison between
spaced and solid text did not discriminate at the width I chose ---
measured, not assumed. Asserting buffer.wrap() directly does, and fails
with left: WordOrGlyph, right: Glyph.
Gates: fmt, workspace clippy -D warnings, diff --check, --lib 1914/0,
crdt 2099/0, protocol 25/0, pmacs-gpu 224/0.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
e755866644