Stage 4 of the QoL arc, framing revision 4 (approved). Under
`truncate`, text past the right edge was UNREACHABLE; moving the cursor
now brings it into view. Automatic only — no commands, no bindings, no
new interaction island (Q#HS2).
THE CONTRACT. `view_left` is an unsnapped per-window display column
(Q#HS7(a)), and each line derives its own effective edge during the
walk it already performs from column 0. Starting at 0 is not laziness:
tab expansion depends on the absolute column from the line start, so a
walk beginning at the edge would put tab stops in the wrong place. The
walk stays line-absolute and only the emit translates.
Where the edge bisects a wide glyph on a given line (Q#HS7(c′)), its
trailing cell paints a styled BLANK rather than a `Continuation` — that
glyph means "the cell before me is a wide glyph's head", and here that
cell is off-screen, so emitting it would name a cell nobody painted.
The mapping designates that cell to the glyph's START byte, which keeps
`byte_at_place` total over visible cells and makes the character the
user scrolled toward clickable. Tabs keep FORWARD rounding (Q#HS7(c″))
— preserved, not chosen.
DECORATIONS TRAVEL WITH THE TEXT. The first version of this commit
translated the base glyph walk and nothing else, which split the frame
in half: at `view_left = 10` a glyph from source column 10 painted at
screen column 0 while its syntax style, diagnostic underline, search
wash and `BufferStyleOverlay` span painted at screen column 10 — or
vanished. Decorations drifting off the characters they describe,
silently, and only once a window had been scrolled.
Every such site carried the same two lines (`start_col.min(max_cols)`,
`end_col.min(max_cols)`), correct only while the left edge was pinned
at zero. `Viewport::visible_cols` is now the one rule all FIVE adopters
share — syntax/LSP styling, diagnostic underlines, search washes,
`BufferStyleOverlay`, and the selection painter — so a future decorator
inherits the translation instead of re-deriving it. It also subsumes
the old `end_col <= start_col` guard rather than sitting beside it.
`StyleSpanOverlay` and `VirtualCellOverlay` are deliberately untouched:
they are documented as viewport-relative, so translating them would be
the mirror defect.
The selection painter was nearly a sixth site with its own copy of the
rule, which I justified by a width it supposedly needed and the
viewport lacked. That was FALSE — the render viewport's
`cell_size.cols` is already `rect.size.cols - gutter_w` and its origin
already sits past the gutter. It now takes that same viewport and drops
its `rect`/`gutter_w` parameters entirely. A canonical rule with one
honest exception is not canonical.
The selection painter had the same defect with a worse failure mode: it
asked `pos_to_display` through the LIVE context, which returns `None`
for a position left of the edge, so a selection beginning off-screen
and reaching into view took `continue` and painted NOTHING. That is the
common shape, not an edge case — select rightward from column 0 past
the window width and the view scrolls with the cursor.
TWO THINGS THE TESTS FOUND, both in `pos_to_display`. My framing note
said a caret sits between characters so never lands inside a glyph;
true for the caret, false for the DESIGNATION direction — the glyph's
start byte must map to its visible trailing cell, so `screen_col` needs
the straddle rule and not a bare subtraction. And the `take == 0` early
return short-circuited the translation entirely, so byte 0 looked
visible at every offset.
`view_left` is inert under `wrap` BY CONSTRUCTION —
`LayoutCtx::effective_left` and `Viewport::left_edge` return 0 while
wrapping — rather than by every caller remembering.
Persisted per leaf at DESKTOP_VERSION 1 (Q#HS5) with both approval
conditions: `#[serde(default)]` and a literal v1 JSON fixture omitting
the field, hand-written because a generated one would gain the field
and prove nothing.
Also: `view_left: window.view_left` in the render viewport, not a
literal 0. My mechanical fill put 0 there and it is EXACTLY the
`aa3cd4d` defect — coordinates and the indicator following the scroll
while the painter stays pinned at column 0.
BITE, per clause. Forcing `bisected = false` fails the multi-line
straddle witness; dropping the backward designation fails the
round-trip witness; removing `#[serde(default)]` fails the v1 fixture;
pinning `visible_cols` to an absolute clamp fails all three decorator
witnesses; restoring the selection painter's live-context lookup fails
the off-screen-start selection witness. Each alone. And with selection
now reading the shared helper, pinning `visible_cols` to an absolute
clamp fails the selection witnesses TOO — which is the check that the
duplication is really gone rather than merely reworded.
One unrelated red, logged as R7 in ci-red-signatures.md — the first
this session with a COMPLETE signature, so a matchable row rather than
a U note. `pmacs-gpu`'s managed-retry attach hit a BrokenPipe once
under full-sweep load and did not reproduce (6 isolated runs plus a
clean 113-target sweep). Per the rerun rule that is intermittence only,
and the row explicitly does not claim harmlessness. Not attributed to
this lane: Stage 4 touches no `pmacs-gpu` file and adds no wire
surface.
Gates: fmt; clippy --workspace --all-targets -D warnings, both
configurations; `cargo test --workspace --no-fail-fast -- --skip
basedpyright` 113 targets exit 0, and the same with --features crdt,
113 targets exit 0; git diff --check. No protocol change, so no version
bump and no protocol-bump matrix.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
ui.line-wrap is buffer-local, and the toggle was built from
pmacs.config.get(name) and pmacs.config.set(name, value) --- both of
which address the GLOBAL layer. The registry's buffer-local surface is
get(name, buf) and set_local(buf, name, value), and the command used
neither.
The result was wrong in both directions at once, which is why it needed
two witnesses rather than one. In a buffer pinned to truncate, the
toggle would read "wrap" from the global layer, decide the next mode is
truncate, and leave that buffer exactly as it was --- while writing
truncate globally and flipping every buffer that had no override of its
own. The command that changes nothing here and everything elsewhere.
Now resolves the buffer ONCE and uses it for both calls. Once matters:
resolving twice would be a narrower version of the same bug, since the
active buffer can change between two calls.
Two witnesses in a new acceptance suite, and both bite against the code
review rejected --- restoring the global-layer toggle fails both while
the default and enum tests keep passing, which is exactly how it
shipped. the_toggle_moves_this_buffer_and_leaves_the_other_alone covers
the leak outward: a second buffer and the global layer must be
untouched. a_pinned_buffer_toggles_from_its_own_value covers the miss
inward: a buffer whose value differs from global must toggle from ITS
value.
Note on the second buffer: there is no Lua buffer-switch, so "the
other" is a buffer that exists but is not shown. That is the case that
matters anyway --- a global write reaches every buffer without an
override, shown or not.
Gates: fmt, workspace clippy -D warnings, diff --check, --lib 1916/0,
line_wrap_acceptance 4/4.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
The setting exists now, and both frontends honor it. This is the commit
that turns the stage on: the grid renderer, the coordinate mapping, and
the GPU were all built and tested against a mode nothing could set.
ui.line-wrap is buffer-local, an enum of wrap and truncate, defaulting
to wrap. A closed set rather than a string, so an unknown value is
impossible rather than handled --- and so adding "word" later is
additive. It lives in ui., not editing.: editing.* is buffer-editing
behavior, this changes only how text is SHOWN, and the two existing
ui.* settings carry a gpu- prefix to mark frontend-specific ones, so
the absence of a prefix is what says "both frontends".
Resolved exactly once. The render loop reads it per window per frame
and records it on the window; the viewport is built FROM that, and
Window::layout_ctx hands the same answer to all twenty coordinate call
sites. Nothing re-resolves, so two callers cannot disagree about one
buffer. The earlier write-back from viewport to window is removed as
circular now that the resolution precedes the viewport.
Semantic frontends are told over LineWrapFacts, gated at v22 in the
producer and again in the daemon write loop. The dedup key is the
(buffer, wrap) PAIR, and that is the whole design rather than a
micro-optimisation: font size is global, so caching it by value is
right, but wrap mode is buffer-local, so a value-keyed cache stays
silent when the user switches from a truncating buffer to a wrapping
one --- a real mode change with no config event behind it.
a_buffer_switch_re_emits_the_wrap_mode pins that, and it bites: keying
the cache on the mode alone fails it while every other test still
passes, which is exactly how the bug would have shipped.
Two existing tests moved, and both moved for the right reason rather
than because they were stale. The semantic allowlist gains the variant,
and the first-frame count goes 7 to 8 --- the second is really an
assertion that the attach trigger works: a semantic frontend that is
not told on its first frame never learns the setting at all.
Also ships ui.toggle-line-wrap, and its status line says the quiet part
--- turning wrapping off makes text past the right edge unreachable
until horizontal scrolling lands in Stage 4. That belongs where a user
sees it, not only in the framing.
Gates: fmt, workspace clippy -D warnings, diff --check, --lib 1916/0,
crdt 2101/0, pmacs-gpu 224/0, tab_width 2/0, folding 21/0, gui_zoom
15/15, full_grid_resync 1/1.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth