Bug 191168 [Regression]Exception occurs when resize masterpage in library
Description: Exception occurs when resize masterpage in library. Build number:2.2.0.v20070606-0630 Regression bug:187443 Steps to reproduce: 1. New a library. 2. Go to Master Page, resize the master page using the ruler. Expected result: 1. Layout works correctly. 2. No exception is thrown out. Error log: An unexpected internal exception occurred.Please see log for detail. Plug-in Provider:Eclipse.org Plug-in Name:BIRT Designer UI Plug-in ID:org.eclipse.birt.report.designer.ui Version:2.2.0.v20070606-0630 Error Code:Error.GUIException.invokedByUnexpectedException Error Message:org.eclipse.birt.report.designer.internal.lib.lalyout.LibraryReportDesignLayout
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
{
			dropElementID( element );
		}
		Iterator iter = new LevelContentIterator( this, element, 1 );
		while ( iter.hasNext( ) )
		{
			DesignElement innerElement = (DesignElement) iter.next( );
			manageId( innerElement, isAdd );
		}
	}
	/**
	 * Gets the location information of the module.
	 * 
	 * @return the location information of the module
	 */
	public String getLocation( )
	{
		assert systemId != null;
		if ( fileName == null )
			return systemId.toString( );
		return systemId + StringUtil.extractFileNameWithSuffix( fileName );
	}
	/**
	 * @param namespace
	 * @return the included library structure with the given namespace
	 */
	public IncludedLibrary findIncludedLibrary( String namespace )
	{
		List libs = getIncludedLibraries( );
		if ( libs == null )