Total deltas for scroll events from mouse wheel are wrong

When scroll events are generated via the mouse wheel, the total delta values returned by the event object are not correct.
The documentation says: "The totalDeltaX and totalDeltaY contain the cumulative values for the whole gesture, zeros for mouse wheel". As you can see in the output of the test program below, the total-deltas for y are not zeros. The values are: e.getDeltaX(), e.getTotalDeltaX(), e.getDeltaY(), e.getTotalDeltaY(), e.getTouchCount()

setOnScroll: 0,000000 0,000000 1,000061 1,000061 0
setOnScroll: 0,000000 0,000000 1,000061 1,000061 0
setOnScroll: 0,000000 0,000000 1,000061 1,000061 0
setOnScroll: 0,000000 0,000000 1,000061 1,000061 0
setOnScroll: 0,000000 0,000000 4,296417 4,296417 0
setOnScroll: 0,000000 0,000000 -1,000061 -1,000061 0
setOnScroll: 0,000000 0,000000 -11,195526 -11,195526 0
setOnScroll: 0,000000 0,000000 -38,627014 -38,627014 0
setOnScroll: 0,000000 0,000000 -50,805664 -50,805664 0
setOnScroll: 0,000000 0,000000 -52,142639 -52,142639 0

This was originally reported in the context of https://bugs.openjdk.java.net/browse/JDK-8236971