mbtiles generates random tiles with black background

[AaronJohnsonSpambox]

What is the bug or the crash?

When trying to generate a topo map using Generate XYZ tiles (MBTiles). Several of the tiles at zoom level 15 or 16 have a black background even though they are PNGs and I use the default transparent background. I discovered the bug on a much more detailed topographic dataset and have pared it down to a much simpler one that still shows the problem.

MB Tiles output:
Results:
QGIS version: 3.26.2-Buenos Aires
QGIS code revision: feec3d3
Qt version: 5.15.3
Python version: 3.9.5
GDAL version: 3.5.1
GEOS version: 3.10.3-CAPI-1.16.1
PROJ version: Rel. 9.0.1, June 15th, 2022
PDAL version: 2.4.2 (git-version: 6cb4e7)
Algorithm started at: 2022-09-10T11:25:46
Algorithm 'Generate XYZ tiles (MBTiles)' starting…
Input parameters:
{ 'BACKGROUND_COLOR' : QColor(0, 0, 0, 0), 'DPI' : 96, 'EXTENT' : '4114751.886400000,4201829.355200000,-380132.886800000,-316419.954400000 [EPSG:3857]', 'METATILESIZE' : 4, 'OUTPUT_FILE' : 'C:/temp/test.mbtiles', 'QUALITY' : 75, 'TILE_FORMAT' : 0, 'ZOOM_MAX' : 16, 'ZOOM_MIN' : 10 }

Using 12 CPU Threads:
Generating tiles for zoom level: 10
Generating tiles for zoom level: 11
Generating tiles for zoom level: 12
Generating tiles for zoom level: 13
Generating tiles for zoom level: 14
Generating tiles for zoom level: 15
Generating tiles for zoom level: 16
Execution completed in 36.76 seconds
Results:
{'OUTPUT_FILE': 'C:/temp/test.mbtiles'}

Loading resulting layers
Algorithm 'Generate XYZ tiles (MBTiles)' finished

Steps to reproduce the issue

Unzip and open the attached project topo.zip and run the Generate XYZ tiles (MBTiles) command:

Input parameters:
{ 'BACKGROUND_COLOR' : QColor(0, 0, 0, 0), 'DPI' : 96, 'EXTENT' : '4114751.886400000,4201829.355200000,-380132.886800000,-316419.954400000 [EPSG:3857]', 'METATILESIZE' : 4, 'OUTPUT_FILE' : 'C:/temp/test.mbtiles', 'QUALITY' : 75, 'TILE_FORMAT' : 0, 'ZOOM_MAX' : 16, 'ZOOM_MIN' : 10 }

Once finished, add the resulting test.mbtiles result to the project and if you zoom into level 15 / 16, and pan around you'll usually see something like this:

Versions

QGIS version
3.26.2-Buenos Aires
QGIS code revision
feec3d3
Qt version
5.15.3
Python version
3.9.5
GDAL/OGR version
3.5.1
PROJ version
9.0.1
EPSG Registry database version
v10.064 (2022-05-19)
GEOS version
3.10.3-CAPI-1.16.1
SQLite version
3.38.1
PDAL version
2.4.2
PostgreSQL client version
unknown
SpatiaLite version
5.0.1
QWT version
6.1.6
QScintilla2 version
2.13.1
OS version
Windows 10 Version 2009

Active Python plugins
db_manager
0.1.20
grassprovider
2.12.99
MetaSearch
0.3.6
processing
2.12.99
sagaprovider
2.12.99

Supported QGIS version

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

New profile

• I tried with a new QGIS profile

Additional context

No response

[Jean-Roc]

I can confirm this behavior using tilesxyzmbtiles processing in QGIS 3.28.2

{
  "area_units": "m2",
  "distance_units": "meters",
  "ellipsoid": "EPSG:7019",
  "inputs": {
    "BACKGROUND_COLOR": "rgba( 0, 0, 0, 0.00 )",
    "DPI": 96,
    "EXTENT": "685164.8273,719222.6358,7044827.5740,7077232.0603 [EPSG:2154]",
    "METATILESIZE": 4,
    "OUTPUT_FILE": "[...]/run_lvl_18.mbtiles",
    "QUALITY": 75,
    "TILE_FORMAT": 0,
    "ZOOM_MAX": 18,
    "ZOOM_MIN": 18
  }

[pfbreton-perso]

I have this problem as well

QGIS version
3.28.3-Firenze
QGIS code revision
c12bcb2
Qt version
5.15.3
Python version
3.9.5
GDAL/OGR version
3.6.2
PROJ version
9.1.1
EPSG Registry database version
v10.076 (2022-08-31)
GEOS version
3.11.1-CAPI-1.17.1
SQLite version
3.39.4
PDAL version
2.4.3
PostgreSQL client version
unknown
SpatiaLite version
5.0.1
QWT version
6.1.6
QScintilla2 version
2.13.1
OS version
Windows 10 Version 2009

[danzig666]

Same here, both with QGIS 3.22.16 and 3.32.0

[Smurfj3]

Issue is also happening for me with version 3.32.1

[alexbruy]

Fixed by #54321.