The row cache rebuilt a string for every line of the file after each edit
and had one production caller left (filetype detection in the ImGui
frontend, which needs only the first line). Removed with it: rows_,
nrows_, the dirty flag set on every edit, ensure_rows_cache and a mutex
guarding only that cache. Tests read lines with GetLineString, Nrows or,
where they compare every line, a test-only LinesForTests().
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Added `test_reflow_undo.cc` to validate undo/redo workflows for reflow operations.
- Introduced `UndoType::InsertRow` in `UndoSystem` for tracking row insertion changes in undo history.
- Updated `UndoNode.h` and `UndoSystem.cc` to support row insertion as a standalone undo step.
- Enhanced reflow paragraph functionality to properly record undo/redo actions for both row deletion and insertion.
- Enabled legacy/extended undo tests in `test_undo.cc` for comprehensive validation.
- Updated `CMakeLists.txt` to include new test file in the build target.
Claude
kyle