Bug 161222 Decoration label should be optional in Gantt Chart
It should not be mandatory to specify a decoration label for Gantt Charts, this can be left blank. Currently the UI and Engine enforce a data definition to be specified for it.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/internal/datafeed/ResultSetWrapper.java
for ( int i = 0; i < idx.size( ); i++ )
							{
								int x = ( (Integer) idx.get( i ) ).intValue( );
								if ( x >= insertPoint )
								{
									idx.set( i, new Integer( x + 1 ) );
								}
							}
							idx.add( new Integer( insertPoint ) );
							
							for ( Iterator itr = idxList.iterator( ); itr.hasNext( ); )
							{
								List gidx = (List) itr.next( );
								for ( int i = 0; i < gidx.size( ); i++ )
								{
									int x = ( (Integer) gidx.get( i ) ).intValue( );
									if ( x >= insertPoint )
									{
										gidx.set( i, new Integer( x + 1 ) );
									}
								}
							}
						}
					}
				}
			}
			idxList.add( idx );
		}