GeoJSON layers not behaving as expected when using ["geometry-type"]

[dschep]

When looking into the impact of maplibre/maplibre-style-spec#519 on Ultra which makes heavy use of GeoJSON sources, I discovered that geojson-vt transforms all single geometry types into multis. This manifests as a bug in MapLibre GL JS.

maplibre-gl-js version: v5 & v4, probably all?

browser: All

Steps to Trigger Behavior

1. Make a GeoJSON source containing MultiPoints and Points (applicable to [Multi]LineString and [Multi]Polygon geometries too)
2. Add a layer using ["geometry-type"] to style Points and MultiPoints differently
3. In v4 all [Multi]Points are rendered as points and in v5 all re rendered as MultiPoints

Link to Demonstration

• v4: https://glitch.com/edit/#!/geometry-type-bug-v4?path=index.html
• v5: https://glitch.com/edit/#!/geometry-type-bug-v5?path=index.html
• expected behavior, faked by including geometry type as a property: https://glitch.com/edit/#!/geometry-type-bug-expected?path=index.html

Expected Behavior

Actual Behavior

v4

v5

[HarelM]

I've checked this locally, I'm still struggling with multipolygon, but otherwise the rest of the stuff looks good.
Note that it looks like geojson-vt is flattening the multi stuff in case they are not needed (probably to improve performance).
If your multi point is more than one point, it should work, I don't know how to categorize this honestly...
See here:
https://jsbin.com/vuguyuvili/2/edit?html,output