Merged cells
- Merge cells across one row or one column with
C-c m; unmerge withC-c u. - Render horizontal and vertical spans with adaptive sizing, vertical centering, and correct Unicode border intersections.
- Navigate merged regions without visiting covered cells; edit and value operations resolve to the anchor cell.
- Preserve merges through row and column edits, save/load, and supported sorting.
- Enter multi-line cell content with
M-RET.
Covered cells remain empty in formulas and CSV output. Destructive merges are rejected instead of silently discarding data, and sorting is rejected when a vertical merge would make row movement ambiguous.
Documentation now includes the merged-cell workflow and a real Emacs screenshot.
Tested with the complete 72-test ERT suite and Emacs byte compilation.