Hi all,

I've been trying to get MapScript for Python working for MapServer 8.0 using 
Visual Studio 2022 and the release-1930-x64 SDK from GISInternals- see issue 
https://github.com/MapServer/MapServer/issues/6628

In summary, whenever you try and save a Mapfile to a file in Python (all 
versions from 2.7 to 3.10 are affected) there is a "Windows fatal exception: 
access violation". 

Note, everything builds fine when using Visual Studio 2019 (and the 
release-1928-x64 SDK) with the same MapServer code. 

The worst thing is that when running a DEBUG version of the code - everything 
works fine. The exception only works in RELEASE version, which means my 
"debugging" involves modifying code, recompiling and rerunning. 

The fact it doesn't work in RELEASE version strongly implies that VS2022 is 
doing some optimization which causes the issue. I'm not sure how best to 
progress this, and hoping someone on the list may have some ideas. 

- With each of the fuzzing fixes, I've been hoping the issue will be resolved. 
Could it be the case that memory is getting corrupted and causing the issue?
- Is it likely the cause is a bug in the MapServer code which causes something 
to be optimized away that shouldn't be?
- Is there any chance there is a bug in VS2022 itself rather than anything in 
MapServer?
- Commenting out various parts of `writeWeb, and `writeFeature` get things 
working again, but there seems to be no logic to this - e.g. commenting out 
half of the `writeLayer` means it works again (with no changes to `writeWeb`), 
but commenting out a single line in `writeWeb` also gets it working, removing 
parts of `writeFeature` also works, a Mapfile with one LAYER works one with 2 
LAYERS doesn't..
- the `writeMapToString` [1] is only called using MapScript. Would it be worth 
adding an option to map2img to dump out an input Mapfile to test this without 
any MapScript?

Thanks for any input!

Seth


[1] 
https://github.com/MapServer/MapServer/blob/e5a53178b056f0da83ec8e5a2e0412a50d0ca3a6/mapfile.c#L5904

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