Fixed #25874 -- Made GEOSGeometry read SRID from GeoJSON input.

django/contrib/gis/gdal/geometries.py

@@ -48,6 +48,7 @@
     GDALException, OGRIndexError, SRSException,
 )
 from django.contrib.gis.gdal.geomtype import OGRGeomType
+from django.contrib.gis.gdal.libgdal import GDAL_VERSION
 from django.contrib.gis.gdal.prototypes import geom as capi, srs as srs_api
 from django.contrib.gis.gdal.srs import CoordTransform, SpatialReference
 from django.contrib.gis.geometry.regex import hex_regex, json_regex, wkt_regex
@@ -87,7 +88,7 @@ def __init__(self, geom_input, srs=None):
                 else:
                     g = capi.from_wkt(byref(c_char_p(wkt_m.group('wkt').encode())), None, byref(c_void_p()))
             elif json_m:
-                g = capi.from_json(geom_input.encode())
+                g = self._from_json(geom_input.encode())
             else:
                 # Seeing if the input is a valid short-hand string
                 # (e.g., 'Point', 'POLYGON').
@@ -139,13 +140,31 @@ def __setstate__(self, state):
     def _from_wkb(cls, geom_input):
         return capi.from_wkb(bytes(geom_input), None, byref(c_void_p()), len(geom_input))
 
+    @staticmethod
+    def _from_json(geom_input):
+        ptr = capi.from_json(geom_input)
+        if GDAL_VERSION < (2, 0):
+            has_srs = True
+            try:
+                capi.get_geom_srs(ptr)
+            except SRSException:
+                has_srs = False
+            if not has_srs:
+                srs = SpatialReference(4326)
+                capi.assign_srs(ptr, srs.ptr)
+        return ptr
+
     @classmethod
     def from_bbox(cls, bbox):
         "Construct a Polygon from a bounding box (4-tuple)."
         x0, y0, x1, y1 = bbox
         return OGRGeometry('POLYGON((%s %s, %s %s, %s %s, %s %s, %s %s))' % (
             x0, y0, x0, y1, x1, y1, x1, y0, x0, y0))
 
+    @staticmethod
+    def from_json(geom_input):
+        return OGRGeometry(OGRGeometry._from_json(force_bytes(geom_input)))
+
     @classmethod
     def from_gml(cls, gml_string):
         return cls(capi.from_gml(force_bytes(gml_string)))

django/contrib/gis/geos/geometry.py

@@ -61,7 +61,9 @@ def __init__(self, geo_input, srid=None):
                 g = wkb_r().read(force_bytes(geo_input))
             elif json_regex.match(geo_input):
                 # Handling GeoJSON input.
-                g = wkb_r().read(gdal.OGRGeometry(geo_input).wkb)
+                ogr = gdal.OGRGeometry.from_json(geo_input)
+                g = ogr._geos_ptr()
+                input_srid = ogr.srid
             else:
                 raise ValueError('String input unrecognized as WKT EWKT, and HEXEWKB.')
         elif isinstance(geo_input, GEOM_PTR):

docs/ref/contrib/gis/geos.txt

@@ -224,9 +224,18 @@ Format                   Input Type
 WKT / EWKT               ``str``
 HEX / HEXEWKB            ``str``
 WKB / EWKB               ``buffer``
-GeoJSON                  ``str``
+GeoJSON_                 ``str``
 =======================  ==========
 
+For the GeoJSON format, the SRID is set based on the ``crs`` member. If ``crs``
+isn't provided, the SRID defaults to 4326.
+
+.. versionchanged:: 2.0
+
+    In older versions, SRID isn't set for geometries initialized from GeoJSON.
+
+.. _GeoJSON: https://tools.ietf.org/html/rfc7946
+
 .. classmethod:: GEOSGeometry.from_gml(gml_string)
 
     .. versionadded:: 1.11

docs/releases/2.0.txt

@@ -71,6 +71,9 @@ Minor features
 * Added the :class:`~django.contrib.gis.db.models.functions.LineLocatePoint`
   function, supported on PostGIS and SpatiaLite.
 
+* Any :class:`~django.contrib.gis.geos.GEOSGeometry` imported from GeoJSON now
+  has its SRID set.
+
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

tests/gis_tests/geos_tests/test_geos.py

@@ -143,7 +143,21 @@ def test_json(self):
                 # Loading jsons to prevent decimal differences
                 self.assertEqual(json.loads(g.json), json.loads(geom.json))
                 self.assertEqual(json.loads(g.json), json.loads(geom.geojson))
-            self.assertEqual(GEOSGeometry(g.wkt), GEOSGeometry(geom.json))
+            self.assertEqual(GEOSGeometry(g.wkt, 4326), GEOSGeometry(geom.json))
+
+    @skipUnless(HAS_GDAL, "GDAL is required.")
+    def test_json_srid(self):
+        geojson_data = {
+            "type": "Point",
+            "coordinates": [2, 49],
+            "crs": {
+                "type": "name",
+                "properties": {
+                    "name": "urn:ogc:def:crs:EPSG::4322"
+                }
+            }
+        }
+        self.assertEqual(GEOSGeometry(json.dumps(geojson_data)), Point(2, 49, srid=4322))
 
     def test_fromfile(self):
         "Testing the fromfile() factory."