Bug 148365 dataset script methods management
Create a report with several datasets (scripted ones, in my case). Select the first one, then choose the script tab ; write some script Save the report Select another one, then choose the script tab (same method ; write some script Save the report Select the first one again, then change the script DONT save Select the over one : the changes made to the first one appears ! => you may save the repor and search for a while before understanding the pb...
UI/org.eclipse.birt.report.designer.ui.editors.schematic/src/org/eclipse/birt/report/designer/internal/ui/editors/script/JSEditor.java
if ( editorUIEnabled == true )
		{
			
			saveModelIfNeeds( );
		}
		if ( selection != null )
		{
			settingText = true;
			Object[] sel = ( (IStructuredSelection) selection ).toArray( );
			if ( sel.length == 1 && sel[0] instanceof DesignElementHandle )
			{
				
				editObject = sel[0];
				palettePage.getSupport( ).setCurrentEditObject( editObject );
				if ( editObject instanceof ExtendedItemHandle )
				{
					disableEditor( );
					cmbExpList.removeAll( );
					cmbItemLastSelected = null;
					getSourceViewer( ).getTextWidget( ).setEnabled( true );
					setEditorText( ( (ExtendedItemHandle) editObject ).getExternalScript( ) );
					context.setVariable( "this", "org.eclipse.birt.report.model.api.ExtendedItemHandle" ); 
				}
				else
				{
					setComboViewerInput( editObject );
					
					cmbItemLastSelected = null;
					setEditorText( "" );