[Oracle] Don't reset srid to -1 when there is no geometry

src/providers/oracle/qgsoracleconn.cpp

@@ -628,7 +628,7 @@ void QgsOracleConn::retrieveLayerTypes( QgsOracleLayerProperty &layerProperty, b
   if ( !onlyExistingTypes )
   {
     layerProperty.types << QgsWkbTypes::Unknown;
-    layerProperty.srids << ( srids.size() == 1 ? *srids.constBegin() : 0 );
+    layerProperty.srids << ( detectedSrid > 0 ? detectedSrid : ( srids.size() == 1 ? *srids.constBegin() : 0 ) );
   }
 }
 

src/providers/oracle/qgsoracleprovider.cpp

@@ -2704,7 +2704,6 @@ bool QgsOracleProvider::getGeometryDetails()
       }
 
       detectedType = QgsWkbTypes::Unknown;
-      detectedSrid = -1;
     }
     else
     {
@@ -2721,15 +2720,13 @@ bool QgsOracleProvider::getGeometryDetails()
         {
           // we need to filter
           detectedType = QgsWkbTypes::Unknown;
-          detectedSrid = -1;
         }
       }
       else
       {
         // geometry type undetermined or not unrequested
         QgsMessageLog::logMessage( tr( "Feature type or srid for %1 of %2 could not be determined or was not requested." ).arg( mGeometryColumn ).arg( mQuery ) );
         detectedType = QgsWkbTypes::Unknown;
-        detectedSrid = -1;
       }
     }
   }

tests/src/python/test_provider_oracle.py

@@ -845,10 +845,32 @@ def testCreateEmptyLayer(self):
         self.assertEqual(query.value(1), 4326)
         query.finish()
 
-        vl = QgsVectorLayer(
-            self.dbconn + ' sslmode=disable table="QGIS"."EMPTY_LAYER" sql=',
-            'test', 'oracle')
+        # no feature, so we cannot guess the geometry type, so the layer is not valid
+        # but srid is set for provider in case you want to add a feature even if the layer is invalid!
+        # layer sourceCrs is empty because the layer is not considered spatial (not know geometry type)
+        vl = QgsVectorLayer(self.dbconn + ' sslmode=disable table="QGIS"."EMPTY_LAYER" (GEOM) sql=', 'test', 'oracle')
+        self.assertFalse(vl.isValid())
+        self.assertEqual(vl.dataProvider().sourceCrs().authid(), "EPSG:4326")
+
+        # so we set the geometry type
+        vl = QgsVectorLayer(self.dbconn + ' sslmode=disable type=POINT table="QGIS"."EMPTY_LAYER" (GEOM) sql=', 'test', 'oracle')
+        self.assertTrue(vl.isValid())
+        self.assertEqual(vl.sourceCrs().authid(), "EPSG:4326")
+
+        f = QgsFeature(vl.fields())
+        f.setGeometry(QgsGeometry.fromWkt('POINT (43.5 1.42)'))
+        vl.dataProvider().addFeatures([f])
+
+        query = QSqlQuery(self.conn)
+        self.assertTrue(query.exec_('SELECT "l"."GEOM"."SDO_SRID" from "QGIS"."EMPTY_LAYER" "l"'))
+        self.assertTrue(query.next())
+        self.assertEqual(query.value(0), 4326)
+        query.finish()
+
+        # now we can autodetect geom type and srid
+        vl = QgsVectorLayer(self.dbconn + ' sslmode=disable table="QGIS"."EMPTY_LAYER" (GEOM) sql=', 'test', 'oracle')
         self.assertTrue(vl.isValid())
+        self.assertEqual(vl.sourceCrs().authid(), "EPSG:4326")
 
     def testCreateAspatialLayer(self):
         """