src/app/qgisapp.cpp

@@ -5449,7 +5449,7 @@ void QgisApp::cancelEdits( QgsMapLayer *layer, bool leaveEditable, bool triggerR
     mSaveRollbackInProgress = true;
 
   mMapCanvas->freeze( true );
-  if ( !vlayer->rollBack() )
+  if ( !vlayer->rollBack( !leaveEditable ) )
   {
     mSaveRollbackInProgress = false;
     QMessageBox::information( 0,

src/app/qgsmaptoolshowhidelabels.cpp

@@ -156,9 +156,15 @@ void QgsMapToolShowHideLabels::showHideLabels( QMouseEvent * e )
 
   QgsDebugMsg( "Number of selected labels or features: " + QString::number( selectedFeatIds.size() ) );
 
+  if ( selectedFeatIds.isEmpty() )
+  {
+    return;
+  }
 
   bool labelChanged = false;
+  QString editTxt = doHide ? tr( "Hid labels" ) : tr( "Showed labels" );
 
+  vlayer->beginEditCommand( editTxt );
   foreach ( const QgsFeatureId &fid, selectedFeatIds )
   {
     if ( showHideLabel( vlayer, fid, doHide ) )
@@ -167,11 +173,16 @@ void QgsMapToolShowHideLabels::showHideLabels( QMouseEvent * e )
       labelChanged = true;
     }
   }
+  vlayer->endEditCommand();
 
   if ( labelChanged )
   {
     mCanvas->refresh();
   }
+  else
+  {
+    vlayer->destroyEditCommand();
+  }
 }
 
 bool QgsMapToolShowHideLabels::selectedFeatures( QgsVectorLayer* vlayer,
@@ -294,14 +305,10 @@ bool QgsMapToolShowHideLabels::showHideLabel( QgsVectorLayer* vlayer,
   }
 
   // different attribute value, edit table
-  QString editTxt = hide ? tr( "Hid label" ) : tr( "Showed label" );
-  vlayer->beginEditCommand( editTxt );
   if ( !vlayer->changeAttributeValue( fid, showCol, curVal, false ) )
   {
     QgsDebugMsg( "Failed write to attribute table" );
-    vlayer->endEditCommand();
     return false;
   }
-  vlayer->endEditCommand();
   return true;
 }

src/app/qgsundowidget.cpp

@@ -61,13 +61,15 @@ void QgsUndoWidget::destroyStack()
 {
   if ( mUndoStack != NULL )
   {
-    mUndoStack->clear();
+    // do not clear undo stack here, just null pointer
     mUndoStack = NULL;
   }
   if ( mUndoView != NULL )
   {
     mUndoView->close();
-    mUndoView = NULL;
+    delete mUndoView;
+    mUndoView = new QUndoView( dockWidgetContents );
+    gridLayout->addWidget( mUndoView, 0, 0, 1, 2 );
   }
 }
 
@@ -99,23 +101,24 @@ void QgsUndoWidget::indexChanged( int curIndx )
   // when individually redoing, differentiate between last redo and a new command added to stack
   bool lastRedo = ( mPreviousIndex == ( mPreviousCount - 1 ) && mPreviousCount == curCount && !canRedo );
 
-  bool debugThis = false;
-  if ( debugThis && offset != 0 )
+  if ( offset != 0 )
   {
-    // '= Rendering =' text is for filtering log results to also only show canvas rendering event
-    QgsDebugMsg( QString( "= Rendering = curIndx : %1" ).arg( curIndx ) );
-    QgsDebugMsg( QString( "= Rendering = offset  : %1" ).arg( offset ) );
-    QgsDebugMsg( QString( "= Rendering = curCount: %1" ).arg( curCount ) );
+    QgsDebugMsg( QString( "curIndx : %1" ).arg( curIndx ) );
+    QgsDebugMsg( QString( "offset  : %1" ).arg( offset ) );
+    QgsDebugMsg( QString( "curCount: %1" ).arg( curCount ) );
     if ( lastRedo )
-      QgsDebugMsg( QString( "= Rendering = lastRedo: true" ) );
+      QgsDebugMsg( QString( "lastRedo: true" ) );
   }
 
-  // avoid canvas refresh when only a command was added to stack (i.e. no user undo/redo action)
-  // or when user has clicked back in view history then added a new command to the stack
+  // avoid canvas redraws when only new command was added to stack (i.e. no user undo/redo action)
+  // or when user has clicked back in QUndoView history then added a new command to the stack
   if ( offset > 1 || ( offset == 1 && ( canRedo || lastRedo ) ) )
   {
     if ( mMapCanvas )
+    {
+      QgsDebugMsg( QString( "trigger redraw" ) );
       mMapCanvas->refresh();
+    }
   }
 
   mPreviousIndex = curIndx;

src/core/qgsvectorlayer.cpp

@@ -2228,7 +2228,7 @@ bool QgsVectorLayer::startEditing()
   mEditBuffer = new QgsVectorLayerEditBuffer( this );
   // forward signals
   connect( mEditBuffer, SIGNAL( layerModified() ), this, SIGNAL( layerModified() ) ); // TODO[MD]: necessary?
-  connect( mEditBuffer, SIGNAL( layerModified() ), this, SLOT( triggerRepaint() ) ); // TODO[MD]: works well?
+  //connect( mEditBuffer, SIGNAL( layerModified() ), this, SLOT( triggerRepaint() ) ); // TODO[MD]: works well?
   connect( mEditBuffer, SIGNAL( featureAdded( QgsFeatureId ) ), this, SIGNAL( featureAdded( QgsFeatureId ) ) );
   connect( mEditBuffer, SIGNAL( featureDeleted( QgsFeatureId ) ), this, SIGNAL( featureDeleted( QgsFeatureId ) ) );
   connect( mEditBuffer, SIGNAL( geometryChanged( QgsFeatureId, QgsGeometry& ) ), this, SIGNAL( geometryChanged( QgsFeatureId, QgsGeometry& ) ) );
@@ -3326,7 +3326,7 @@ const QStringList &QgsVectorLayer::commitErrors()
   return mCommitErrors;
 }
 
-bool QgsVectorLayer::rollBack()
+bool QgsVectorLayer::rollBack( bool deleteBuffer )
 {
   if ( !mEditBuffer )
   {
@@ -3344,8 +3344,12 @@ bool QgsVectorLayer::rollBack()
 
   updateFields();
 
-  delete mEditBuffer;
-  mEditBuffer = 0;
+  if ( deleteBuffer )
+  {
+    delete mEditBuffer;
+    mEditBuffer = 0;
+    undoStack()->clear();
+  }
   emit editingStopped();
 
   // invalidate the cache so the layer updates properly to show its original

src/core/qgsvectorlayer.h

@@ -713,8 +713,10 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     bool commitChanges();
     const QStringList &commitErrors();
 
-    /** Stop editing and discard the edits */
-    bool rollBack();
+    /** Stop editing and discard the edits
+     * @param deleteBuffer whether to delete editing buffer (added in 1.9)
+     */
+    bool rollBack( bool deleteBuffer = true );
 
     /**get edit type*/
     EditType editType( int idx );

src/core/qgsvectorlayereditbuffer.cpp

@@ -445,10 +445,9 @@ void QgsVectorLayerEditBuffer::rollBack()
   if ( !isModified() )
     return;
 
-  while ( L->undoStack()->canUndo() )
-  {
-    L->undoStack()->undo();
-  }
+  // limit canvas redraws to one by jumping to beginning of stack
+  // see QgsUndoWidget::indexChanged
+  L->undoStack()->setIndex( 0 );
 
   Q_ASSERT( mAddedAttributes.isEmpty() );
   Q_ASSERT( mDeletedAttributeIds.isEmpty() );