Bug 193886 NPE is thrown when preview external CSS style in ppt[1205]
engine/org.eclipse.birt.report.engine.emitter.ppt/src/org/eclipse/birt/report/engine/emitter/ppt/PPTRender.java
{
			if ( imageNames.containsKey( imageContent.getName( ) ) )
			{
				imageName = (String) imageNames.get( imageContent.getName( ) );
			}
			else
			{
				
				String extension = imageContent.getExtension( );
				imageName = imageTitle + "." + extension;
				imageNames.put( imageContent.getName( ), imageName );
				imageExtensions.put( imageContent.getName( ), extension );
				recordFileLists( imageName );
				currentImageContents.add( imageContent );
			}
		}
		double width = pptMeasure( image.getWidth( ) );
		double height = pptMeasure( image.getHeight( ) );
		double x = layoutAreaX2PPT( imageX );
		
		double y = layoutAreaY2PPT( imageY );
		try
		{
			pptOutput.write( ( "<v:shape id=3D'" + ( shapeCount ) + "' type=3D'#r'\n" ).getBytes( ) ); 
			pptOutput.write( ( " style=3D'position:absolute;left:" + x + "pt;top:" + y + "pt;width:" + width + "pt;height:" + height + "pt'\n" ).getBytes( ) ); 
			pptOutput.write( ( " filled=3D'f' stroked=3D'f'>\n" ).getBytes( ) ); 
			pptOutput.write( ( "<v:imagedata src=3D\"" + imageName + "\" o:title=3D\"" + imageTitle + "\"/>\n" ).getBytes( ) ); 
			pptOutput.write( ( "<o:lock v:ext=3D'"
					+ "edit"
					+ "' aspectratio=3D't"