Bug 147676 [regression]Visibility set in the first col will affect the second col
Description: Visibility set in the first col will affect the second col Steps to reproduce: 1. Insert a grid(3*3), insert contents to each cell. 2.Set the first col to hide all in visibility and preview Expected result: Only the first col is hidden. Actual result: The second col is hidden, too. If you set the second col in step2, the third col will disappear.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/content/ListContainerExecutor.java
IReportItemExecutor ret = new ItemExecutorWrapper(childExecutor, childContent);
				childContent = null;
				childExecutor = null;
				needUpdate = true;
				return ret;
			}
			if(currentRunIn!=null)
			{
				needUpdate = true;
				return currentRunIn.getNextChild( );
			}
			assert(false);
			return null;
			
		}
		public boolean hasNextChild( )
		{
			if(!needUpdate)
			{
				return hasNext;
			}
			if(currentRunIn!=null)
			{
				if(currentRunIn.hasNextChild( ))
				{
					hasNext = true;
					needUpdate = false;
					return hasNext;
				}
				else