Applied patch to fix bug #1747. Thanks to gcarrillo!

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@10978 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/app/qgisapp.cpp

@@ -1662,6 +1662,9 @@ void QgisApp::setupConnections()
   connect( mMapLegend, SIGNAL( currentLayerChanged( QgsMapLayer* ) ),
            mMapTools.mNodeTool, SLOT( currentLayerChanged( QgsMapLayer* ) ) );
 
+  // connect map layer registry signal to identify
+  connect( QgsMapLayerRegistry::instance(), SIGNAL( layerWillBeRemoved( QString ) ),
+           mMapTools.mIdentify, SLOT( removeLayer( QString ) ) );
 
   //signal when mouse moved over window (coords display in status bar)
   connect( mMapCanvas, SIGNAL( xyCoordinates( QgsPoint & ) ), this, SLOT( showMouseCoordinate( QgsPoint & ) ) );

src/app/qgsmaptoolidentify.cpp

@@ -46,6 +46,8 @@ QgsMapToolIdentify::QgsMapToolIdentify( QgsMapCanvas* canvas )
   // set cursor
   QPixmap myIdentifyQPixmap = QPixmap(( const char ** ) identify_cursor );
   mCursor = QCursor( myIdentifyQPixmap, 1, 1 );
+
+  mLayer = 0; // Initialize mLayer, useful in removeLayer SLOT
 }
 
 QgsMapToolIdentify::~QgsMapToolIdentify()
@@ -511,3 +513,22 @@ void QgsMapToolIdentify::editFeature( QgsFeature &f )
   delete ad;
   mCanvas->refresh();
 }
+
+void QgsMapToolIdentify::removeLayer( QString layerID )
+{
+  if ( mLayer )
+  {
+    if ( mLayer->type() == QgsMapLayer::VectorLayer )
+    {
+      if ( mLayer->getLayerID() == layerID )
+      {
+        if ( mResults )
+        {
+          mResults->clear();
+          delete mRubberBand;
+          mRubberBand = 0;
+        }
+      }
+    }
+  }
+}

src/app/qgsmaptoolidentify.h

@@ -112,6 +112,8 @@ class QgsMapToolIdentify : public QgsMapTool
     // Let us know when the QgsIdentifyResults dialog box has been closed
     void resultsDialogGone();
 
+    // Check if the mLayer is removing from canvas to clear the results dialog
+    void removeLayer( QString );
 
 };