Merge pull request #4594 from boundlessgeo/postgis_merge_features_fix#15741

Fix Postgis Merge selected features regression (fix #15741)

Author: alexbruy

src/core/qgsvectordataprovider.h

@@ -52,6 +52,7 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
     Q_OBJECT
 
     friend class QgsTransaction;
+    friend class QgsVectorLayerEditBuffer;
 
   public:
 

src/core/qgsvectorlayereditbuffer.cpp

@@ -302,6 +302,35 @@ bool QgsVectorLayerEditBuffer::commitChanges( QStringList& commitErrors )
   // no                 yes                   => changeAttributeValues
   // yes                yes                   => changeFeatures
 
+  // to fix https://issues.qgis.org/issues/15741
+  // first of all check if feature to add is compatible with provider type
+  // this check have to be done before all checks to avoid to clear internal
+  // buffer if some of next steps success.
+  if ( success && !mAddedFeatures.isEmpty() )
+  {
+    if ( cap & QgsVectorDataProvider::AddFeatures )
+    {
+    for ( QgsFeature f : mAddedFeatures )
+      {
+        if (( ! f.geometry() ) || ( f.geometry()->isEmpty() ) ||
+            ( f.geometry()->wkbType() == provider->geometryType() ) )
+          continue;
+
+        if ( ! provider->convertToProviderType( f.geometry() ) )
+        {
+          commitErrors << tr( "ERROR: %n feature(s) not added - geometry type is not compatible with the current layer.", "not added features count", mAddedFeatures.size() );
+          success = false;
+          break;
+        }
+      }
+    }
+    else
+    {
+      commitErrors << tr( "ERROR: %n feature(s) not added - provider doesn't support adding features.", "not added features count", mAddedFeatures.size() );
+      success = false;
+    }
+  }
+
   //
   // update geometries
   //

tests/src/python/CMakeLists.txt

@@ -106,6 +106,7 @@ ADD_PYTHON_TEST(PyQgsUnitTypes test_qgsunittypes.py)
 ADD_PYTHON_TEST(PyQgsVectorColorRamp test_qgsvectorcolorramp.py)
 ADD_PYTHON_TEST(PyQgsVectorFileWriter test_qgsvectorfilewriter.py)
 ADD_PYTHON_TEST(PyQgsVectorLayer test_qgsvectorlayer.py)
+ADD_PYTHON_TEST(PyQgsVectorLayerEditBuffer test_qgsvectorlayereditbuffer.py)
 ADD_PYTHON_TEST(PyQgsZonalStatistics test_qgszonalstatistics.py)
 ADD_PYTHON_TEST(PyQgsMapLayerRegistry test_qgsmaplayerregistry.py)
 ADD_PYTHON_TEST(PyQgsVirtualLayerProvider test_provider_virtual.py)