After version 4.5.0 requests with 404 are not emitted in map.on('error')

[ElGreeno]

maplibre-gl-js version: 4.6.0
browser: Chrome

Steps to Trigger Behavior

1. Create a MapLibre map with vector tiles that have data only up to a certain zoom level (e.g., zoom level 16).
2. Attach an event listener to capture errors:

map.on('error', (e) => {
    console.log('ERROR', e);
});

3. Zoom in past the available tile data (e.g., zoom beyond level 16 where 404 responses are expected for missing tiles).

Expected Behavior

• When a tile request results in a 404 response due to missing data at higher zoom levels, the map.on('error') event should emit the error as it did in versions prior to 4.5.0.
• This allowed overzooming tiles and keeping the previous zoom level’s data visible.

Actual Behavior

• In version 4.6.0, map.on('error') no longer emits any error when tile requests result in 404 responses.
• This causes tiles with no data at certain zoom levels to disappear.

[HarelM]

Can you please create a jsbin with the relevant example?
I don't see anything in the changelog after 4.5 that could've introduce this regression, so this is strange...

[ElGreeno]

Zoom beyond level 15 to see the difference.

4.4.0: https://jsbin.com/wuzivoc/1/edit?html,output

4.6.0: https://jsbin.com/puwuwob/2/edit?html,output

[HarelM]

I'm having a hard time finding the diffs. Can you please create a minimal reproduction with as little layer and code as possible?

[ElGreeno]

4.4.0: https://jsbin.com/puwuwob/5/edit?html,output

4.6.0: https://jsbin.com/qewoyug/2/edit?html,output

[HarelM]

Ah, so the version that "stopped" working is 4.5.0.
In this case the following PR is probably the cause of this, and it also looks like something related to this issue about ajax error serialization:

• ajaxerror not serialized properly #4211

The above PR solves a different issue, which we should avoid breaking again.
Feel free to look into it.