Setting very high cache size crashes QGIS at startup

[lhilarides]

What is the bug or the crash?

Using QGIS 3.34.5 on Windows 11, I changed my cache size (settings --> options --> network) from 2GB to 12GB ( value of 12048000 KiB). I have plenty of free diskspace (>400 GB). After changing that setting I was no longer able to start QGIS, it wouldn't even show the loading screen. After removing the [cache] section entirely from the qgis.ini file in my QGIS profile, things were back to normal again.

Steps to reproduce the issue

1. Change network cache size to 12GB or more
2. Close QGIS
3. Start QGIS (it won't start)
4. Clear [cache] section from qgis.ini in the profile
5. Start QGIS (it will start now)

Versions

3.34.5 and also reproducible on 3.36.2

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

[kentstanton]

Also occurs for me. Running 3.34.4-Prizren or 3.26.2 on Windows 11.

Setting the network cache value to anything larger than 2090000 causes QGIS to crash on startup as described above.

In QGIS3.ini the cache values:
works when the value is set to 2000000 in the UI
[cache]
size=@variant(\0\0\0\x81\0\0\0\0z\x12\0\0)

Fails when the value is set to 2100000 in the UI
[cache]
size="@variant(\0\0\0\x81\xff\xff\xff\xff\x80,\x80\0)"

[agiudiceandrea]

On Windows (OSGeeo4W), setting the value 2100000, the following debug message printed:
[28444] qgsnetworkaccessmanager.cpp(759) : (QgsNetworkAccessManager::setupDefaultProxyAndCache) [305ms] maximumCacheSize: -2144567296

QgsSettings().value('cache/size',None) returns -2144567296.