Bug 182687 Exception thrown out when preview crosstab with toc setting
When preview crosstab which has set the toc property, exception will be thrown. Engine need to handle the case during toc processing while no IR object is associated with current content object. java.lang.NullPointerException at org.eclipse.birt.report.engine.executor.ReportItemExecutor.startTOCEntry(ReportItemExecutor.java:591) at org.eclipse.birt.report.engine.executor.ExtendedItemExecutor.execute(ExtendedItemExecutor.java:140) at org.eclipse.birt.report.engine.internal.executor.l18n.LocalizedReportItemExecutor.execute(LocalizedReportItemExecutor.java:36) at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layoutChildren(HTMLPageLM.java:124) at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layout
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ReportItemExecutor.java
for ( int i = 0; i < visibility.count( ); i++ )
			{
				VisibilityRuleDesign rule = visibility.getRule( i );
				String expr = rule.getExpression( );
				Object result = null;
				if ( expr != null )
				{
					result = evaluate( expr );
				}
				if ( result == null || !( result instanceof Boolean ) )
				{
					logger
							.log(
									Level.WARNING,
									"The following visibility expression does not evaluate to a legal boolean value: {0}", 
									rule.getExpression( ) );
					continue;
				}
				boolean isHidden = ( (Boolean) result ).booleanValue( );
				
				
				if ( !isHidden )
				{
					continue;
				}
				
				if ( isFirst )
				{
					isFirst = false;
				}