layers, where individual features may have point geometries
Not sure if this is a bug in ArcGIS server (probably, yeah, let's
go with definitely. I couldn't check the source to see.) But in
general QGIS approach is to be forgiving and do our best to
make up for badly behaved servers).
See https://community.esri.com/thread/14037
Sometimes, calling some layout methods, results in sip being inable
to downcast the items to their correct type, resulting only
in a QgsLayoutItem object.
This works around the problem, albeit in an incredibly hacky way.
This class is useful for plugins and other areas of QGIS code which
want to expose a limited browser interface (e.g. a vector layer
only type layer picker)
Also add unit tests
Some rationale on this change...
Previously when applying a "regular" subset string, ie. one that is only the
content of a where clause, we issued a full "SELECT * FROM layer WHERE subsetstring",
resulting in a OGR SQL layer. The caveat of that is that most OGR drivers
will have issues retaining the original FID. A hack consisting in adding a
{original_fid_name} as orig_ogc_fid to the select columns was introduced in
4ce2cf1744
to try to retain the original FID, but this added a lot of complexity. And
actually, in the case of the OGR GPKG driver, it caused it to still be confused
when analyzing the column definition of the resulting layer, since it sees
2 FID columns despite the renaming (one included in the '*' wildcard, and the
one of orig_ogc_fid), which caused it to use sequential FID numbering (the
driver when seeing more than once a column that is the FID column assumes that
some cross join is done, and thus that FID are unreliable)
A simpler and more robust (crossing fingers!) approach in that case is
just to use OGR_L_SetAttributeFilter() instead of GDALDatasetExecuteSQL().
Some care must be taken to cancel the filter when removing the subset
filter, or in QgsOgrFeatureIterator when combining with the filter
expression coming from the request, but besides that, this is more
straightforward, and actually solves #20136
