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 ( null == color
				|| 0f == width
				|| "none".equalsIgnoreCase( lineStyle ) ) 
		{
			return;
		}
		if ( lineStyle.equalsIgnoreCase( "solid" )
				|| lineStyle.equalsIgnoreCase( "dashed" )
				|| lineStyle.equalsIgnoreCase( "dotted" )
				|| lineStyle.equalsIgnoreCase( "double" ) )
		{
			drawRawLine( startX, startY, endX, endY, width, color, lineStyle );
		}
		else
		{
			
			
			
			drawRawLine( startX, startY, endX, endY, width, color, "solid" );
		}
	}
	/**
	 * Draws a line with the line-style specified in advance from the start
	 * position to the end position with the given linewidth, color, and style
	 * on the PPT. If the line-style is NOT set before invoking this method,
	 * "solid" will be used as the default line-style.
	 * 
	 * @param startX
	 *            the start X coordinate of the line