Rebuild sort order when display-name format changes

[eduralph]

Summary

User impact: Change how names are displayed (for example switching from surname-first to given-name-first in Preferences), and the People list keeps showing rows in the old sort order until you close and reopen the database. The names update on screen, but the ordering is stale, so the list looks wrongly sorted.

This makes the People list re-sort itself as soon as the display-name (or place) format changes, without needing a reopen.

Reported in Mantis #9267.

What to look at

The flat People list caches its computed sort order to stay fast; the fix invalidates that cache when the name/place format changes so the list re-sorts immediately. To reproduce: open the People view, then Edit → Preferences → Display and change the Display Name format — pre-fix the row order is unchanged until reopen, post-fix the rows reorder in place.

Root cause

The flat People list caches the (sortkey, handle) map across rebuilds to avoid recomputing sort keys when the database hasn't changed (e.g. search or filter narrowing). When the user changes the Display Name format in Edit→Preferences→Display, the sort key itself changes (e.g. surname-first → given-first), but the view's rebuild path (nameformat-changed → build_tree) redisplays the rows without invalidating the cache, leaving the list sorted by the previous format until the database is reopened.

Fix

Add a rebuild_sort() method to the model layer:

1. BaseModel (gramps/gui/views/treemodels/basemodel.py:59-71) — define rebuild_sort() as a no-op default. The hierarchical (tree) model clears and re-adds every row on each rebuild, so it re-sorts from scratch; the flat model caches the sort order and needs to override this to invalidate the cache.

2. FlatBaseModel (gramps/gui/views/treemodels/flatbasemodel.py:494-497, :548-562) — add a _sort_dirty flag initialized False in __init__. Override rebuild_sort() to set it True. In _rebuild_search and _rebuild_filter, change the cache-reuse guard from if not allkeys: to if self._sort_dirty or not allkeys: (lines 612 and 647), and clear the flag after recomputing.

3. BasePersonView (gramps/plugins/lib/libpersonview.py:191-202) — add a _format_changed() handler that calls self.model.rebuild_sort() (guarded for the pre-build None case) before build_tree(). Wire it to both nameformat-changed and placeformat-changed signals.

The same view callback is safe on both flat and tree person models because rebuild_sort() now exists on the common base; the tree model's no-op does nothing (it re-sorts on every rebuild anyway), and the flat model's override sets the flag. This addresses iteration 1's rejection: iteration 1 added rebuild_sort() only to FlatBaseModel, so a name-format change on the Person Tree view would raise AttributeError at runtime.

Verification

• Claim: changing the display-name (or place) format re-sorts the People list immediately, on both the flat and tree person models, without a database reopen and without raising.
• Checked: on upstream/maintenance/gramps61 —
  • gramps/gui/views/treemodels/basemodel.py:59-71 — rebuild_sort() default
  • gramps/gui/views/treemodels/flatbasemodel.py:491-626 — cache initialization and reuse guards
  • gramps/plugins/lib/libpersonview.py:178-202 — signal routing and format-changed handler
• Test: core regression test gramps/gui/views/treemodels/test/flatbasemodel_sort_test.py (new), two classes —
  • FlatBaseModelSortRebuildTest drives the production _rebuild_search() / _rebuild_filter() over a real FlatNodeMap with a mutable sort-key function (surname vs. given name; the orders are reverses, so re-sort is unambiguous). Pre-fix rebuild_sort() doesn't exist → AttributeError (RED); post-fix rows re-sort to the new format (GREEN).
  • TreeModelSortRebuildSafetyTest guards the iteration-1 rejection: asserts BaseModel provides rebuild_sort() and that TreeBaseModel.rebuild_sort() is a harmless no-op (returns None without raising). Pre-fix → AttributeError on tree format change; post-fix → GREEN.
  • Advisory AT-SPI interface test engine/interface/test_bug_9267_name-format-sort.py launches the flat People list, captures the display-order Gramps-ID sequence, applies a format change via UI automation, and re-captures — pre-fix IDs unchanged (FAIL), post-fix IDs reordered (PASS).

Fixes #9267