Bug 131243 Open invalid report design.
Open a invalid report design should switch to XML Source editor page and can't switch to other pages, when the source is correct user can switch to layout and other pages.
UI/org.eclipse.birt.report.designer.ui.editors/src/org/eclipse/birt/report/designer/ui/editors/MultiPageReportEditor.java
getEditorInput( ) );
		if ( provider != null )
		{
			setPartName( provider.getInputPath( getEditorInput( ) )
					.lastSegment( ) );
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.part.EditorPart#isSaveAsAllowed()
	 */
	public boolean isSaveAsAllowed( )
	{
		return getActivePageInstance( ).isSaveAsAllowed( );
	}