If a non-pushed source node (inline view) is located over a projecting node (windowfunctionproject, join, group, or a select node) the resulting construction of the projection/projection indexes will be incorrect or fail - as the input elements will not match the output elements that have been set to the views elements. For example with the exception:
java.lang.AssertionError: ASSERTION FAILED: expected reference to be not null
Note that not all nodes should be the first child under a source. For example, join/group should not appear there (typically it will be one of project/windowfunctionproject/limit/sort/unionall/select). Other child nodes besides windowfunctionproject/select could have issues, since we are not specifically coding to use a different set of output vs. original elements such as with ProjectNode that holds elements and selectSymbols respectively.