FlatGeobuf: does not support lco ENCODING

[tobwen]

Expected behavior and actual behavior.

Right now, it's not possbile to set the encoding using -lco ENCODING. It's unknown if FlatGeobuf supports UTF-8 only by design.

Steps to reproduce the problem.

ogr2ogr -F FlatGeobuf test_01.fgb test.geojson -lco ENCODING=UTF-8
ogr2ogr -F FlatGeobuf test_02.fgb test.geojson

Testfile (test.geojson)

{ "type": "FeatureCollection", "features": [ { "type": "Feature", "properties": { "name": "Straße ÄÖÜß €" }, "geometry": { "type": "Point", "coordinates": [ 0,0 ] } } ]}

Operating system

Microsoft Windows 10, 64 bit - Version 10.0.17763.678

GDAL version and provenance

GDAL 3.1.0dev, released 2019/99/99 from OSGeo4W (update 2020-02-17)

[bjornharrtell]

FlatGeobuf only supports UTF-8 by design.

Can you clarify what the expected behavior is here and supply the test data?

[tobwen]

Warning: This now will be offtopic here and I should move it to QGIS' issue list. It just wasn't clear to me, whether_FlatGeobuf_ supports other encodings than UTF-8.

There is a snippet in my initial post, which can be used to reproduce the problem. I've loaded the FGB into QGIS and it used "system" encoding as a standard, like it does on most shapefiles. I first thought, FlatGeobuf is behaving to a shapefile, which allows any encoding. But I think, it's an issue of the way, GDAL (or QGIS itself) identifies the codepage.

Since you clarifyed, FlatGeobuf can be UTF-8 only, it should be reported to QGIS that the incoming dataset is UTF-8. I don't know, if this is QGIS' or GDAL's job. It's correctly handled in GDAL, so there seems to be the missing flat for QGIS that the incoming data is encoded in UTF-8.

[tobwen]

Ah, maybe here we go? qgis/QGIS#34381

[bjornharrtell]

Nice find @tobwen, I've often been fooled by how QGIS tries to guess shapefile encoding. Now, if it will solve this issue I'm not sure yet.

[bjornharrtell]

@tobwen if you have the possiblity, please test with QGIS nightly on Windows and report back.

[nyalldawson]

I don't think there's a QGIS issue here -- even in versions with the confusing shapefile encoding handling, these only applied to shapefile sources (not other ogr sources)

[rouault]

@bjornharrtell OGRFlatGeoBufLayer::TestCapability() should likely advertize OLCStringsAsUTF8

[bjornharrtell]

@rouault thanks that definitely seems to be the right thing to do.