- C0 controls and DEL were passed to ncurses, which acted on them: a
carriage return moved to column 0 and the line padding then erased
the text, so every line of a CRLF file drew blank, and a backspace
ate the previous character. They are now drawn in caret notation
(^M, ^H, ^?) and counted as two cells. C1 controls (and stray bytes
0x80-0x9F, which decode to them; U+009B is CSI) are drawn as '?'.
- The width rule lives in TermWidth.h and is shared by the renderer's
drawing loop, its cursor placement and the command layer's
horizontal scrolling and mouse mapping, which also disagreed on NUL
and invalid bytes.
- GUI config: columns/rows must be 1..1000 and the font size a finite
4..200 (TOML 'size = inf' and huge values were accepted, leading to
UB in float-to-int conversion and int overflow downstream).
Verified in tmux: a CRLF file now shows 'first line^M' where the
baseline showed a blank line.
Audit findings B9 (and the CR/BS case from the follow-up review).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- fsync is never retried. After a writeback error Linux may mark the
pages clean, so a retried fsync could succeed although the data was
lost, and the rename then replaced a good file with a bad one.
- New files get 0666 & ~umask instead of mkstemp's 0600. Replaced files
keep their mode (file-type bits masked) and, best effort, their owner
and group.
- Saving through a symlink writes the link's target instead of
replacing the link with a regular file (SaveAs did not resolve it).
- A file with several hard links is rewritten in place, so the other
names see the new content (as vim does by default).
- Save-as (prompt and ':save-as') asks before replacing any existing
file other than the buffer's own; it used to ask only for unnamed
buffers. Save-and-quit refuses to overwrite a file changed on disk,
like save. The first save of a new file records the saved undo state.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
libstdc++'s std::regex matcher recurses about once per matched
character, so '.*', 'a+' or '(a|b)*' on a line of a few tens of
thousands of characters (minified JS/JSON) overflowed the 8 MiB stack
and crashed the editor from the regex search prompt or regex replace.
Regex search and regex replace now run their matching on a worker
thread with a 1 GiB reserved stack (RunWithLargeStack; the caller
waits, so nothing is shared concurrently). Renderers skip regex match
highlighting on lines over 10,000 bytes. Catastrophic backtracking
(e.g. (a*)*b) is still possible: std::regex has no time limit.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Motion and delete commands read rows through RowsView (on-demand,
version-cached) instead of Buffer::Rows(), which rebuilt every line of
the file after each edit. On a 500k-line buffer after an edit:
backspace/delete/motions 80-90 ms -> ~0.1 ms; C-u 3000 C-d 273 s ->
0.25 s. Whole-buffer search scans keep Rows() (cached between edits).
- While a prompt is open only prompt-aware and view-only commands run.
Others edited the buffer behind the prompt (bypassing the read-only
check) or switched/closed buffers under a pending confirmation, which
then acted on the wrong buffer. The ':' command path now applies the
read-only check too.
- Pasting into a prompt (ImGui) flattens line breaks to spaces instead
of emitting Newline, which accepted the prompt and sent the rest of
the paste to the buffer (or ran replace-all).
- The mark region clamps both ends; a stale mark past the end of the
buffer is treated as end of buffer. This fixes kill-region deleting
the wrong text and leaving the cursor past end-of-line.
- Kill-line with a count stops at end of buffer instead of killing
lines above the cursor (regression from the D3 change).
- Undo groups nest, so SmartNewline in visual-line mode is one step.
- Word motions and word deletion treat non-ASCII bytes as word
characters and so never split a UTF-8 character.
- The universal-argument count saturates at 1,000,000 instead of
overflowing int.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
Consolidation rewrites pieces without changing content or offsets but
invalidated the line index, so once a buffer passed the piece limit
every edit paid a full rescan again. A moved-from table kept the index
of the text it gave away, and Insert now updates that index in place,
producing ranges past the end of its buffer.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
Every edit bumped the buffer version (through SetDirty) and called
InvalidateFrom(0), so all cached spans and line states were discarded
and stateful highlighters re-lexed from row 0 to the viewport on each
keystroke.
Buffer mutators now report the row they changed (edited_at_), which
bumps the version and tells the engine to drop only rows from there
down; a row's highlighting depends only on rows above it. A version
change that arrives without that notice still clears everything, so a
missed path cannot show stale spans. The engine keeps states as a
contiguous vector and caches spans for every row it lexes. SetDirty no
longer touches the version: the edits themselves do, including undo
and redo back to the saved state (D9 still holds; its test now checks
the highlighting itself).
Typing near the end of a 100k-line C++ file: 46.3 ms -> 0.14 ms of
highlighting work per keystroke.
Audit finding P3.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- PieceTable::Insert/Delete adjust a valid line index directly (shift
later line starts, add or drop starts for inserted or deleted
newlines) instead of invalidating it, which forced a byte-by-byte
rescan of the whole buffer on the next line query. On a 38 MB,
1M-line buffer, insert + line query drops from 14.7 ms to 0.28 ms.
- The terminal and ImGui renderers fetch only the rows they draw
(Nrows + GetLineString) instead of Buffer::Rows(), which rebuilt a
string for every line of the file on the first frame after each edit.
Qt's line-count uses switch to Nrows().
ImGuiRenderer.cc was syntax-checked with g++ and clang++ against the
vendored ImGui headers; the GUI targets could not be built here (no
SDL2 or Qt6).
Audit findings P1, P2.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Backspace and delete-char remove a whole UTF-8 character (they
removed one byte, leaving an invalid lead byte in the file), and
record the full character for undo.
- Left/right step over whole characters; up/down snap the column to a
character boundary and clamp the row, which also removes an unsigned
underflow in move-down when the cursor was past the last row.
- Horizontal scroll offsets are computed in display cells, the way the
terminal renderer draws (tabs, wide characters), instead of bytes, so
long non-ASCII lines no longer scroll to blank with the cursor off
screen. The mouse column mapping uses the same measure.
Audit findings B5, B6.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Regex replace-all, reflow and kill-region replaced or deleted whole
rows, which added or left a stray newline when the text ended on a
last line without one. They now edit the byte range in place.
- Regex replace-all no longer matches the empty position after a final
newline. Before, a zero-width pattern such as ^ matched it, added a
line, and matched the new empty last row again: the editor hung.
- Kill-line on the last row kills an unterminated line with the newline
before it, and does nothing on the empty row after a final newline
(it used to record an undo step that added a line).
- The visual-line newline records its splits as one undo step, and
places the cursor correctly for a repeat count.
- Buffer::delete_text computes its byte range directly instead of
materializing every line it spans.
Audit findings D3, D4, D5.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
A secondary GUI window shared the primary's buffer vector but attached
buffers through its own SwapManager. Closing the window destroyed that
manager while buffers still held its recorders, so the next edit called
into freed memory; Rehome through the wrong manager also dropped
journaling for the primary's buffers.
Audit finding M3.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
Claude