Lowercase letters in WFS response

[simre-gst]

What is the bug or the crash?

Hello,
I'm not sure if it's a bug, but I think it's very unfortunate that all attribute field names in WFS responses are lowercase now.

Steps to reproduce the issue

Add WFS such as:
https://wfs.datafordeler.dk/MATRIKLEN2/MatGaeldendeOgForeloebigWFS/1.0.0/WFS?username=USER&password=PASS
note: requires login to https://datafordeler.dk/ (free)

Then in QGIS 3.34 the Jordstykke layer has this attribute table:

While in QGIS 3.40 it looks like this:

This breaks some plugins, but it also breaks the documentation for the services.

Versions

QGIS version
3.40.1-Bratislava
QGIS code revision
989853a

Libraries
Qt version
5.15.13
Python version
3.12.7
GDAL/OGR version
3.9.3
PROJ version
9.5.0
EPSG Registry database version
v11.016 (2024-08-31)
GEOS version
3.13.0-CAPI-1.19.0
SQLite version
3.46.1
PDAL version
2.8.1
PostgreSQL client version
16.2
SpatiaLite version
5.1.0
QWT version
6.3.0
QScintilla2 version
2.14.1
OS version
Windows 10 Version 2009

Active Python plugins
Dataforsyningen
0.5
geosearch_dk
2.0.4
pluginbuilder3
3.2.1
plugin_reloader
0.11
skraafoto
1.0
db_manager
0.1.20
processing
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

[rouault]

I haven't checked but I suspect this layer uses complex features, or at least a complex enough schema, for the GDAL GMLAS driver being used underneath by QGIS. The GMLAS driver by default modifies identifiers to be compatible of PostgreSQL. I believe this setting https://github.com/OSGeo/gdal/blob/638b0a70da7af1ddf8e26c5b477a5136e30a783b/ogr/ogrsf_frmts/gmlas/data/gmlasconf.xml#L37 could be modified to avoid that (not totally sure though), but currently that can't be directly used/tested as the QGIS WFS provider provides itself a non-default configuration file to the GMLAS driver