Change #273328

Comments

Cleanup work

  Key changes:

  - Added a prepared-layout API in layout-custom.c:
      - Parse and validate once.
      - Retain the validated temporary tree.
      - Apply through a no-failure, consuming operation.

  - Multi-window layouts prepare every record before changing any window.
  - Removed duplicate parsing, recalculation, and notification work.
  - Restored very old legacy layouts where pane IDs are absent.
  - Added structural validation before and after surplus-cell pruning.
  - Split pane-ID uniqueness and matching logic.
  - Renamed LAYOUT_FORMAT_NEW to LAYOUT_FORMAT.
  - Kept LAYOUT_CELL_HIDDEN as the requested serialization/rendering marker
    only.

  - Updated documentation and regression coverage, including:
      - Historical bb62,... layouts.
      - Malformed discarded cells.
      - Maximum parser nesting depth.

Changed files

• cmd-select-layout.c
• layout-custom.c
• regress/layout-custom.sh
• tmux.1
• tmux.h