Merge pull request #5879 from pblottiere/refrelfilter_218

[bugfix]  Fixes auto select foreign key when filters are updated in QgsRelationReferenceWidget

Author: pblottiere

src/gui/editorwidgets/qgsrelationreferencewidget.cpp

@@ -941,6 +941,18 @@ void QgsRelationReferenceWidget::filterChanged()
   }
 
   mFilterModel->setFilteredFeatures( featureIds );
+
+  if ( mChainFilters && mComboBox->count() > 0 )
+  {
+    if ( scb->currentIndex() == 0 )
+    {
+      mComboBox->setCurrentIndex( 0 );
+    }
+    else if ( mComboBox->count() > 1 )
+    {
+      mComboBox->setCurrentIndex( 1 );
+    }
+  }
 }
 
 void QgsRelationReferenceWidget::addEntry()

tests/src/gui/testqgsrelationreferencewidget.cpp

@@ -174,8 +174,20 @@ void TestQgsRelationReferenceWidget::testChainFilter()
 
   // set the filter for "raccord" and then reset filter for "diameter". As
   // chain filter is activated, the filter on "raccord" field should be reset
+  cbs[0]->setCurrentIndex( 0 );
+  QCOMPARE( w.mComboBox->currentIndex(), 0 );
+
+  cbs[0]->setCurrentIndex( cbs[0]->findText( "iron" ) );
+  QCOMPARE( w.mComboBox->currentIndex(), 1 );
+
+  cbs[1]->setCurrentIndex( cbs[1]->findText( "120" ) );
+  QCOMPARE( w.mComboBox->currentIndex(), 1 );
+
   cbs[2]->setCurrentIndex( cbs[2]->findText( "brides" ) );
+  QCOMPARE( w.mComboBox->currentIndex(), 1 );
+
   cbs[1]->setCurrentIndex( cbs[1]->findText( "diameter" ) );
+  QCOMPARE( w.mComboBox->currentIndex(), 0 );
 
   // combobox should propose NULL, 10 and 11 because the filter is now:
   // "material" == 'iron'