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
transInput = new TranscoderInput( imageInput );
						}
						imageData = new byte[imageInput.available( )];
						imageInput.read( imageData );
						break;
					case IImageContent.IMAGE_URL :
						if ( imageContent.getURI( ) == null )
							return;
						if ( imageContent.getURI( ).endsWith( ".svg" ) )
						{
							isSvg = true;
							transInput = new TranscoderInput( imageContent.getURI( ) );
						}
						imageData = imageContent.getData( );
						break;
					case IImageContent.IMAGE_NAME :
					case IImageContent.IMAGE_EXPRESSION :
						if ( imageContent.getData( ) == null
								|| imageContent.getURI( ) == null )
							return;
						if ( imageContent.getURI( ).endsWith( ".svg" ) )
						{
							isSvg = true;
							transInput = new TranscoderInput( new ByteArrayInputStream( imageContent.getData( ) ) );
						}
						imageData = imageContent.getData( );
						break;
					default :
						imageData = imageContent.getData( );
						break;