QgsVectorFileWriter: fix DGN creation (fixes #19722, fixes #19723)

Author: rouault

src/core/qgsvectorfilewriter.cpp

@@ -140,6 +140,10 @@ QgsVectorFileWriter::QgsVectorFileWriter( const QString &vectorFileName,
 
 bool QgsVectorFileWriter::supportsFeatureStyles( const QString &driverName )
 {
+  if ( driverName == QLatin1String( "MapInfo MIF" ) )
+  {
+    return true;
+  }
 #if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,3,0)
   GDALDriverH gdalDriver = GDALGetDriverByName( driverName.toLocal8Bit().constData() );
   if ( !gdalDriver )
@@ -151,7 +155,7 @@ bool QgsVectorFileWriter::supportsFeatureStyles( const QString &driverName )
 
   return CSLFetchBoolean( driverMetadata, GDAL_DCAP_FEATURE_STYLES, false );
 #else
-  return driverName == QLatin1String( "DXF" ) || driverName == QLatin1String( "KML" ) || driverName == QLatin1String( "MapInfo File" ) || driverName == QLatin1String( "MapInfo MIF" );
+  return driverName == QLatin1String( "DXF" ) || driverName == QLatin1String( "KML" ) || driverName == QLatin1String( "MapInfo File" );
 #endif
 }
 
@@ -415,16 +419,16 @@ void QgsVectorFileWriter::init( QString vectorFileName,
   // disable encoding conversion of OGR Shapefile layer
   CPLSetConfigOption( "SHAPE_ENCODING", "" );
 
-  if ( driverName == QLatin1String( "DGN" ) )
-  {
-    mLayer = OGR_DS_GetLayerByName( mDS.get(), "elements" );
-  }
-  else if ( action == CreateOrOverwriteFile || action == CreateOrOverwriteLayer )
+  if ( action == CreateOrOverwriteFile || action == CreateOrOverwriteLayer )
   {
     mLayer = OGR_DS_CreateLayer( mDS.get(), layerName.toUtf8().constData(), mOgrRef, wkbType, options );
-    if ( newLayer )
+    if ( newLayer && mLayer )
       *newLayer = OGR_L_GetName( mLayer );
   }
+  else if ( driverName == QLatin1String( "DGN" ) )
+  {
+    mLayer = OGR_DS_GetLayerByName( mDS.get(), "elements" );
+  }
   else
   {
     mLayer = OGR_DS_GetLayerByName( mDS.get(), layerName.toUtf8().constData() );

src/gui/ogr/qgsvectorlayersaveasdialog.cpp

@@ -758,7 +758,11 @@ QStringList QgsVectorLayerSaveAsDialog::datasourceOptions() const
     }
   }
 
-  return options + mOgrDatasourceOptions->toPlainText().split( '\n' );
+  QString plainText = mOgrDatasourceOptions->toPlainText().trimmed();
+  if ( !plainText.isEmpty() )
+    options += plainText.split( '\n' );
+
+  return options;
 }
 
 QStringList QgsVectorLayerSaveAsDialog::layerOptions() const
@@ -813,7 +817,11 @@ QStringList QgsVectorLayerSaveAsDialog::layerOptions() const
     }
   }
 
-  return options + mOgrLayerOptions->toPlainText().split( '\n' );
+  QString plainText = mOgrLayerOptions->toPlainText().trimmed();
+  if ( !plainText.isEmpty() )
+    options += plainText.split( '\n' );
+
+  return options;
 }
 
 QgsAttributeList QgsVectorLayerSaveAsDialog::selectedAttributes() const

tests/src/python/test_qgsvectorfilewriter.py

@@ -116,6 +116,9 @@ def testWriteWithLongLongField(self):
         idx = vl.fields().indexFromName('fldlonglong')
         self.assertEqual(vl.getFeature(1).attributes()[idx], 2262000000)
 
+        del vl
+        os.unlink(filename + '.gpkg')
+
     def testWriteWithBoolField(self):
 
         # init connection string
@@ -156,6 +159,9 @@ def testWriteWithBoolField(self):
         self.assertEqual(vl.getFeature(1).attributes()[idx], 1)
         self.assertEqual(vl.getFeature(2).attributes()[idx], 0)
 
+        del vl
+        os.unlink(filename + '.gpkg')
+
     def testDateTimeWriteShapefile(self):
         """Check writing date and time fields to an ESRI shapefile."""
         ml = QgsVectorLayer(
@@ -939,6 +945,43 @@ def testOverwriteGPKG(self):
             options)
         self.assertEqual(write_result, QgsVectorFileWriter.NoError, error_message)
 
+    def testCreateDGN(self):
+        ml = QgsVectorLayer('Point?crs=epsg:4326', 'test', 'memory')
+        provider = ml.dataProvider()
+        feat = QgsFeature()
+        feat.setGeometry(QgsGeometry.fromPointXY(QgsPointXY(10, 10)))
+        provider.addFeatures([feat])
+
+        filename = os.path.join(str(QDir.tempPath()), 'testCreateDGN.dgn')
+        crs = QgsCoordinateReferenceSystem()
+        crs.createFromId(4326, QgsCoordinateReferenceSystem.EpsgCrsId)
+        rc, errmsg = QgsVectorFileWriter.writeAsVectorFormat(ml, filename, 'utf-8', crs, 'DGN')
+
+        # open the resulting file
+        vl = QgsVectorLayer(filename, '', 'ogr')
+        self.assertTrue(vl.isValid())
+        self.assertEqual(vl.featureCount(), 1)
+        del vl
+
+        # append
+        options = QgsVectorFileWriter.SaveVectorOptions()
+        options.driverName = 'DGN'
+        options.layerName = 'test'
+        options.actionOnExistingFile = QgsVectorFileWriter.AppendToLayerNoNewFields
+        write_result, error_message = QgsVectorFileWriter.writeAsVectorFormat(
+            ml,
+            filename,
+            options)
+        self.assertEqual(write_result, QgsVectorFileWriter.NoError, error_message)
+
+        # open the resulting file
+        vl = QgsVectorLayer(filename, '', 'ogr')
+        self.assertTrue(vl.isValid())
+        self.assertEqual(vl.featureCount(), 2)
+        del vl
+
+        os.unlink(filename)
+
 
 if __name__ == '__main__':
     unittest.main()