Vector tiles icons are missing when style uses local sprite directory

[GallPeters]

What is the bug or the crash?

When loading vector tiles style which contains reference to a local sprite directory, rules (style's layers) using sprite's icons are not visible. I have tried to use absolute path, relative path and even file-url (e.g. "file:///") without any success. However, when serving sprite directory using a localhost (python-http server), style can be viewed propperly.

Steps to reproduce the issue

Archive.zip

1. Extract zipped directory.

2. Drag & drop tiles.mbtiles file to QGIS canvas.

3. Load style.json to mbtiles layer's symbology.

4. View the layer and expect missing icons as follow:

   

5. Initialize local http-sever using python command (inside cmd shell) which serve the extracted directory (e.g. python -m http.server 9000 -d "path\to\extracted\directory".

6. Change the sprite url inside style.json so it will point to the served directory as follow:

   

7. Save the change.

8. Load style.json to mbtiles layer's again.

9. View the layer and expect visible icons as follow:

   

Versions

QGIS version 3.34.7-Prizren QGIS code revision 6f7d735c Qt version 5.15.13 Python version 3.12.3 GDAL/OGR version 3.9.0 PROJ version 9.4.0 EPSG Registry database version v11.004 (2024-02-24) GEOS version 3.12.1-CAPI-1.18.1 SQLite version 3.45.1 PDAL version 2.6.3 PostgreSQL client version 16.2 SpatiaLite version 5.1.0 QWT version 6.2.0 QScintilla2 version 2.14.1 OS version Windows 11 Version 2009

Active Python plugins db_manager 0.1.20 grassprovider 2.12.99 MetaSearch 0.3.6 processing 2.12.99

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QGIS version 3.36.3-Maidenhead QGIS code revision 2df96554 Qt version 5.15.13 Python version 3.12.3 GDAL/OGR version 3.9.0 PROJ version 9.4.0 EPSG Registry database version v11.004 (2024-02-24) GEOS version 3.12.1-CAPI-1.18.1 SQLite version 3.45.1 PDAL version 2.6.3 PostgreSQL client version 16.2 SpatiaLite version 5.1.0 QWT version 6.2.0 QScintilla2 version 2.14.1 OS version Windows 11 Version 2009

Active Python plugins cartography_tools 1.2.1 cartolinegen 3.2.2 data_sources_panel 0.2.1 geocatbridge 4.4.1 HCMGIS 24.1.12 lockzoom 3.0.4 MemoryLayerSaver 5.0.2 OSMDownloader 1.0.3 postgisQueryBuilder 2.0.1 postgis_geoprocessing 0.9 qgis-maptiler-plugin 3.3 Qgis2threejs 2.7.3 QuickOSM 2.2.3 quick_map_services 0.19.34 qwc2_tools v1.3.0 searchlayers 3.0.16 SRTM-Downloader 3.2.2 zoom_level 0.3.1 db_manager 0.1.20 MetaSearch 0.3.6 processing 2.12.99

Supported QGIS version

• [X] I'm running a supported QGIS version according to the roadmap.

New profile

• [X] I tried with a new QGIS profile

Additional context

No response

[GallPeters]

I have found the cause of the problem. I use QGIS that is installed on Windows (11) and it turns out that QGIS (or is it mapbox/json spec?) can not handle the colon (:) that comes after the drive name in the folder path:

If I define the folder which contains the style and sprite files as a network path QGIS finds the folder and render sprite's icon properly :

This is strange behavior due to the fact that ESRI's vtpk holds style and sprite files in a regular folder (not a network path) and still manages to fetch and render icons properly.