[antonsoo]

Return an empty iterator for valid empty FeatureCollections and readable zero-feature datasets. A spatial filter can produce these selections, and RFC 7946 section 3.3 permits an empty features array. Currently, GeoDataFrames and collections are rejected by a truthiness check, while empty files fail the vector-source probe.

For inputs that are not existing local paths, parse inline GeoJSON before probing file sources. This keeps the documented file-only engine setting from sending JSON text to fiona.open(), and preserves original feature IDs instead of replacing them through GDAL.

The regressions and recorded polygon/point selections cover both engines, GeoJSON/GeoPackage/Shapefile and in-memory inputs. All 131 tests pass with older dependencies; current Affine/Shapely require the same two existing deprecation-warning filters as the baseline. Ruff checks/formatting, an installed-wheel replay and composition with the NaN-nodata correction pass. Working geometry, properties and query/statistics results remain unchanged.

Existing local paths retain priority even when the filename is valid JSON, such as 123 or {}; regressions cover string and Path inputs.

[antonsoo]

I found a dispatch regression while auditing this change: local filenames such as 123 and {} could be parsed as JSON. The updated commit gives existing local paths priority and adds string/Path regressions. Both file engines and all 256 earlier recorded-data configurations still pass; the full suite now has 131 passing tests with the previously noted dependency-warning filters.