Bug 195335 Multithreads issue
a static hashmap in class HTMLServerImageHandler has not been synchronized which may leads to that the same images are handled(eg: write to disk) multiple times.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/HTMLServerImageHandler.java
}
			catch ( IOException e )
			{
				log.log( Level.SEVERE, e.getMessage( ), e );
			}
			
			if ( imageURL.indexOf( "?" ) > 0 ) 
			{
				ret = imageURL + fileName;
			}
			else if ( imageURL.endsWith( "/" ) ) 
			{
				ret = imageURL + fileName;
			}
			else
			{
				ret = imageURL + "/" + fileName; 
			}
			if ( needMap )
			{
				map.put( mapID, ret );
			}
		}
		else
		{
			ret = handleTempImage( image, prefix, needMap );
		}
		return ret;
	}
	protected String handleTempImage( IImage image, String prefix,