Problems with format guessing when writing Shapefile/GeoJSON

I am sorry in advance, because this is dumb, but it is a bug.

If I have a shapefile of name foo.shp (plus auxiliary files) and try to create a GeoJSON file named foo.shp (because I forgot to update the filename), I will get a Shapefile named OgrGeoJSON.shp (plus aux. files) instead. Here is a test script:

import fiona
from fiona.crs import from_epsg
import glob

outdir = "/tmp"
file = "O"  # "O" so that we will see the OgrGeoJSON files in globbing

p = {
    'geometry': {'coordinates': (370262, 5615696), 'type': 'Point'},
    'id': '0', 'properties': {}, 'type': 'Feature'
}

schema = {'geometry': 'Point', 'properties': {}}

with fiona.open(f"{outdir}/{file}.shp", "w", crs=from_epsg(25832), schema=schema, driver="ESRI Shapefile") as sink:
    sink.write(p)
        
print(glob.glob(f"{outdir}/{file}*"))
# -> ['/tmp/O.prj', '/tmp/O.cpg', '/tmp/O.dbf', '/tmp/O.shx', '/tmp/O.shp']

# here we have .shp but driver="GeoJSON"
with fiona.open(f"{outdir}/{file}.shp", "w", crs=from_epsg(25832), schema=schema, driver="GeoJSON") as sink:
    sink.write(p)
        
print(glob.glob(f"{outdir}/{file}*"))
# -> ['/tmp/OgrGeoJSON.prj', '/tmp/OgrGeoJSON.cpg', '/tmp/OgrGeoJSON.dbf', '/tmp/OgrGeoJSON.shx', '/tmp/OgrGeoJSON.shp', '/tmp/O.prj', '/tmp/O.cpg', '/tmp/O.dbf', '/tmp/O.shx', '/tmp/O.shp']

I would have expected either an error or the foo.shp file being overwritten (aux. files left in place for extra confusion because screw the Shapefile format clutter).

The other way around is not much better as Fiona now tries to overwrite the existing foo.geojson with another GeoJSON even though ESRI Shapefile was set as the driver.

import fiona
from fiona.crs import from_epsg
import glob

outdir = "/tmp"
file = "O"  # "O" so that we will see the OgrGeoJSON files in globbing

p = {
    'geometry': {'coordinates': (370262, 5615696), 'type': 'Point'},
    'id': '0', 'properties': {}, 'type': 'Feature'
}

schema = {'geometry': 'Point', 'properties': {}}

with fiona.open(f"{outdir}/{file}.geojson", "w", crs=from_epsg(25832), schema=schema, driver="GeoJSON") as sink:
    sink.write(p)
        
print(glob.glob(f"{outdir}/{file}*"))
# -> ['/tmp/O.geojson']

# here we have .geojson but driver="ESRI Shapefile"
with fiona.open(f"{outdir}/{file}.geojson", "w", crs=from_epsg(25832), schema=schema, driver="ESRI Shapefile") as sink:
    sink.write(p)
        
print(glob.glob(f"{outdir}/{file}*"))
# -> DriverIOError: GeoJSON driver doesn't support creating a layer on a read-only datasource

To me, the driver parameter should have precedence as it is such an explicite declaration of the user.

[sgillies]

I’m going to close this one as we are many GDAL versions on. We can reopen or create a new issue if needed.

[kannes]

Sure thing! If someone runs into it again they will hopefully find the issue and shout.