Fix some model issues

src/gui/processing/qgsprocessingtoolboxmodel.cpp

@@ -152,9 +152,11 @@ void QgsProcessingToolboxModel::repopulateRecentAlgorithms( bool resetting )
   if ( !mRecentNode )
     return;
 
-  if ( !resetting && rowCount( index( 0, 0 ) ) > 0 )
+  QModelIndex recentIndex = index( 0, 0 );
+  const int prevCount = rowCount( recentIndex );
+  if ( !resetting && prevCount > 0 )
   {
-    beginRemoveRows( index( 0, 0 ), 0, rowCount( index( 0, 0 ) ) );
+    beginRemoveRows( recentIndex, 0, prevCount - 1 );
     mRecentNode->deleteChildren();
     endRemoveRows();
   }
@@ -174,7 +176,7 @@ void QgsProcessingToolboxModel::repopulateRecentAlgorithms( bool resetting )
 
   if ( !resetting )
   {
-    beginInsertRows( index( 0, 0 ), 0, recentAlgorithms.count() - 1 );
+    beginInsertRows( recentIndex, 0, recentAlgorithms.count() - 1 );
   }
 
   for ( const QgsProcessingAlgorithm *algorithm : qgis::as_const( recentAlgorithms ) )
@@ -199,7 +201,7 @@ void QgsProcessingToolboxModel::providerAdded( const QString &id )
   if ( !isTopLevelProvider( id ) )
   {
     int previousRowCount = rowCount();
-    beginInsertRows( QModelIndex(), previousRowCount + 1, previousRowCount + 1 );
+    beginInsertRows( QModelIndex(), previousRowCount, previousRowCount );
     addProvider( provider );
     endInsertRows();
   }

tests/src/gui/CMakeLists.txt

@@ -44,6 +44,10 @@ INCLUDE_DIRECTORIES(SYSTEM
   ${QSCINTILLA_INCLUDE_DIR}
 )
 
+IF(ENABLE_MODELTEST)
+  INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/tests/qt_modeltest)
+ENDIF(ENABLE_MODELTEST)
+
 #note for tests we should not include the moc of our
 #qtests in the executable file list as the moc is
 #directly included in the sources

tests/src/gui/testqgsprocessingmodel.cpp

@@ -22,6 +22,12 @@
 
 #include <QtTest/QSignalSpy>
 #include "qgstest.h"
+
+#ifdef ENABLE_MODELTEST
+#include "modeltest.h"
+#endif
+
+
 class DummyAlgorithm : public QgsProcessingAlgorithm
 {
   public:
@@ -134,6 +140,10 @@ void TestQgsProcessingModel::testModel()
   QgsProcessingRecentAlgorithmLog recentLog;
   QgsProcessingToolboxModel model( nullptr, &registry, &recentLog );
 
+#ifdef ENABLE_MODELTEST
+  new ModelTest( &model, this ); // for model validity checking
+#endif
+
   QCOMPARE( model.columnCount(), 1 );
   QCOMPARE( model.rowCount(), 1 );
   QVERIFY( model.hasChildren() );