Bug 121003 Data source property binding error
When there are two data source property binding, the second binding cannot be set.The exception will be reported: org.eclipse.birt.report.model.api.metadata.PropertyValueException: The value "odaDataSource" already exists. at org.eclipse.birt.report.model.api.validators.StructureListValidator.doCheckStructureList(StructureListValidator.java:223) at org.eclipse.birt.report.model.api.validators.StructureListValidator.validateForAdding(StructureListValidator.java:96) at org.eclipse.birt.report.model.core.DesignElement.checkStructureList(DesignElement.java:2642) at org.eclipse.birt.report.model.command.PropertyCommand.addItem(PropertyCommand.java:444) at org.eclipse.birt.report.model.api.DesignElementHandle.setPropertyBinding(DesignElementHandle.java:2086) at org.eclipse.birt.report.designer.internal.ui.dialogs.DataSourcePropertyBindingPage.performOk(DataSourcePropertyBindingPage.java:192)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/validators/StructureListValidator.java
List list = (List) element.getLocalProperty( module, propDefn );
		return doCheckStructureList( module, element, propDefn, list, null );
	}
	/**
	 * Checks all structures in the specific property whose type is structure
	 * list property type.
	 * @param module
	 *            the module
	 * @param element
	 *            the design element to validate
	 * @param propDefn
	 *            the property definition of the list property
	 * @param list
	 *            the structure list to check
	 * @param toAdd
	 *            the structure to add. This parameter maybe is
	 *            <code>null</code>.
	 * 
	 * @return the error list
	 */
	private List doCheckStructureList( Module module,
			DesignElement element, IPropertyDefn propDefn, List list,
			IStructure toAdd )
	{
		boolean checkList = toAdd == null;
		List errorList = new ArrayList( );
		if ( list == null || list.size( ) == 0 )
			return errorList;
		assert propDefn != null;
		assert propDefn.getTypeCode( ) == PropertyType.STRUCT_TYPE;