CRSes
May result in some CRSes which were previously identified as known standard CRSes
now being shown as User CRSes, but they aren't the same to we can't equate them.
If previously identified CRSes are showing as User CRSes now, then we should
investigate these upstream in the proj or gdal libraries, and get all fixes
in place upstream rather then trying to do this in QGIS code (which is
inevitably going to end up with an unmaintainable mess)
Previously whenever an unknown CRS (i.e. something which couldn't
be matched a standard or user crs) was encountered then it would
automatically be saved to the user's custom CRS database.
This meant that over time, the custom CRS database would fill
with dozens of random entries. Even a clean QGIS install would
pollute the custom projection list with a bunch of automatically
created random CRS definitions!
Instead, never auto save CRSes to the custom projection database.
Only projections which users have manually created via the custom
projection dialog should ever be available as User CRSes.
These should NOT be used, and auth:code or WKT definitions used instead.
Unfortunately some use of these methods are very heavily entangled around
other code, so we can't deprecate all of them until 4.0
Constructing CRS using Postgis srids is highly discouraged,
and instead CRSes should always be constructed using auth:id
codes or WKT strings.
QGIS 4.0: The logic should be isolated into the postgres
provider alone, and not exposed to stable API
Honestly, a failing server test (apparently totally unrelated)
and bisect took me here and I don't really get all the
intricancies of the crs read order in the project XML loading
process, but this commit fixes the test.
This is one of the notable occasions in which a test saved our a**.
instead of just proj strings
WKT strings are lossless and allow definition of a much wider range
of projections than are possible using proj strings.
A new combo box in the Custom Projections dialog allows users to
choose whether the new projection is defined using a WKT or PROJ string.
If possible, the current projection definition is automatically converted
when the combo box is changed by the user.
Also fixes#25918 in the process
