Bug 168026 Still use the existing data binding even though the aggregate is different
I had a table in which a data binding which aggregates on a group. When I insert a new data item in the report, although the expressions are same, it aggregates on All, then it refered to the existing data binding. The expected behavior would be a new data binding is created with different aggregates.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/api/ReportItemHandleTest.java
structHandle = (StructureHandle) rules.next( );
		assertNull( structHandle );
		
		DataItemHandle dataHandle = (DataItemHandle) designHandle
				.findElement( "bodyData" ); 		
		rules = dataHandle.visibilityRulesIterator( );
		structHandle = (StructureHandle) rules.next( );
		assertNotNull( structHandle );
		
		memberHandle = structHandle.getMember( HideRule.FORMAT_MEMBER );
		assertEquals( DesignChoiceConstants.FORMAT_TYPE_ALL, memberHandle
				.getStringValue( ) );
		memberHandle = structHandle.getMember( HideRule.VALUE_EXPR_MEMBER );
		assertNull( memberHandle.getStringValue( ) );
		
		structHandle = (StructureHandle) rules.next( );
		assertNotNull( structHandle );
		memberHandle = structHandle.getMember( HideRule.FORMAT_MEMBER );
		assertEquals( DesignChoiceConstants.FORMAT_TYPE_PDF, memberHandle
				.getStringValue( ) );
		
		memberHandle = structHandle.getMember( HideRule.VALUE_EXPR_MEMBER );
		assertNull( memberHandle.getStringValue( ) );
	}
	/**
	 * Tests to write hide rules to the design file.
	 * 
	 * @throws Exception
	 *             if open/write the design file with IO errors.
	 */