QGIS search provider returns no results for layers loaded from other themes

[dominik-warch]

The QGIS feature search only returns results when the searched layer is natively part of the active theme's WMS. If the same layer is added to the map by importing it from another theme (e.g. via the theme switcher import), the search finds no results, even though the layer is visually present and functional on the map.

All my searches are currently defined as defaultSearchProviders so the searches themselves are always visible.

[manisandro]

The search providers are currently associated to a theme, not to a theme layer. Indeed knowing which layers are referenced by a QGIS search is currently only possible by parsing the filter expression. Changing this will require some non trivial refactoring.

(As a long term goal, it might make sense to move away from a configuration format where layers are bound to a theme, but rather keep each layer as a self-contained entity, which includes relevant searches, edit configs, etc, and a theme is just a collection of such layers).