Don't report a postgis import was successful when the user cancels

it mid-way through

python/core/qgsvectorlayerimport.sip

@@ -3,9 +3,6 @@
  There are two possibilities how to use this class:
  1. static call to QgsVectorFileWriter::writeAsShapefile(...) which saves the whole vector layer
  2. create an instance of the class and issue calls to addFeature(...)
-
- Currently supports only writing to shapefiles, but shouldn't be a problem to add capability
- to support other OGR-writable formats.
  */
 class QgsVectorLayerImport
 {
@@ -30,7 +27,8 @@ class QProgressDialog;
       ErrInvalidLayer,
       ErrInvalidProvider,
       ErrProviderUnsupportedFeature,
-      ErrConnectionFailed
+      ErrConnectionFailed,
+      ErrUserCancelled, /*!< User cancelled the import*/
     };
 
     /** Write contents of vector layer to a different datasource */

src/core/qgsvectorlayerimport.cpp

@@ -333,11 +333,14 @@ QgsVectorLayerImport::importLayer( QgsVectorLayer* layer,
     progress->setRange( 0, layer->featureCount() );
   }
 
+  bool cancelled = false;
+
   // write all features
   while ( fit.nextFeature( fet ) )
   {
     if ( progress && progress->wasCanceled() )
     {
+      cancelled = true;
       if ( errorMessage )
       {
         *errorMessage += '\n' + QObject::tr( "Import was canceled at %1 of %2" ).arg( progress->value() ).arg( progress->maximum() );
@@ -436,5 +439,10 @@ QgsVectorLayerImport::importLayer( QgsVectorLayer* layer,
     }
   }
 
-  return errors == 0 ? NoError : ErrFeatureWriteFailed;
+  if ( cancelled )
+    return ErrUserCancelled;
+  else if ( errors > 0 )
+    return ErrFeatureWriteFailed;
+
+  return NoError;
 }

src/core/qgsvectorlayerimport.h

@@ -29,9 +29,6 @@ class QProgressDialog;
  There are two possibilities how to use this class:
  1. static call to QgsVectorFileWriter::writeAsShapefile(...) which saves the whole vector layer
  2. create an instance of the class and issue calls to addFeature(...)
-
- Currently supports only writing to shapefiles, but shouldn't be a problem to add capability
- to support other OGR-writable formats.
  */
 class CORE_EXPORT QgsVectorLayerImport
 {
@@ -50,7 +47,8 @@ class CORE_EXPORT QgsVectorLayerImport
       ErrInvalidLayer,
       ErrInvalidProvider,
       ErrProviderUnsupportedFeature,
-      ErrConnectionFailed
+      ErrConnectionFailed,
+      ErrUserCancelled, /*!< User cancelled the import*/
     };
 
     /** Write contents of vector layer to a different datasource */

src/providers/postgres/qgspostgresdataitems.cpp

@@ -207,6 +207,8 @@ bool QgsPGConnectionItem::handleDrop( const QMimeData * data, QString toSchema )
 
   QStringList importResults;
   bool hasError = false;
+  bool cancelled = false;
+
   QgsMimeDataUtils::UriList lst = QgsMimeDataUtils::decodeUriList( data );
   Q_FOREACH ( const QgsMimeDataUtils::Uri& u, lst )
   {
@@ -235,6 +237,8 @@ bool QgsPGConnectionItem::handleDrop( const QMimeData * data, QString toSchema )
       err = QgsVectorLayerImport::importLayer( srcLayer, uri.uri( false ), "postgres", &srcLayer->crs(), false, &importError, false, nullptr, progress );
       if ( err == QgsVectorLayerImport::NoError )
         importResults.append( tr( "%1: OK!" ).arg( u.name ) );
+      else if ( err == QgsVectorLayerImport::ErrUserCancelled )
+        cancelled = true;
       else
       {
         importResults.append( QString( "%1: %2" ).arg( u.name, importError ) );
@@ -254,7 +258,12 @@ bool QgsPGConnectionItem::handleDrop( const QMimeData * data, QString toSchema )
 
   qApp->restoreOverrideCursor();
 
-  if ( hasError )
+  if ( cancelled )
+  {
+    QMessageBox::information( nullptr, tr( "Import to PostGIS database" ), tr( "Import cancelled." ) );
+    refresh();
+  }
+  else if ( hasError )
   {
     QgsMessageOutput *output = QgsMessageOutput::createMessageOutput();
     output->setTitle( tr( "Import to PostGIS database" ) );