Channel join behaving in surprising (incorrect?) ways

[antoniofabio]

join seems to drop duplicate keys, and gives inconsistent results when used with remainder: true.
There's a similar (stale) issue which I don't think got to the core of the problem, which is not about outer vs inner join.

Given this code:

left = Channel.from(
  ['k1', 'l1'],
  ['k1', 'l2'],
  ['k2', 'l3']
  )
right = Channel.from(
  ['k1', 'r1'],
  ['k2', 'r2']
  )

left.join(right).view()

I get this output:

[k1, l1, r1]
[k2, l3, r2]

while I would have expected this:

[k1, l1, r1]
[k1, l2, r1]
[k2, l3, r2]

The result of using 'remainder: true' is even more puzzling. This code:

left = Channel.from(['k1', 'l1'], ['k1', 'l2'], ['k2', 'l3'], ['k3', 'l4'])
right = Channel.from(['k1', 'r1'], ['k2', 'r2'])

left.join(right, remainder: true).view()

results into this:

[k1, l1, r1]
[k2, l3, r2]
[k1, l2, null]
[k3, l4, null]

The same behavior is shown by the 'cross' operator.