[tahoe-lafs-trac-stream] [Tahoe-LAFS] #3719: tahoe_cp doesn't correctly determine when it needs to copy bytes

[Tahoe-LAFS]

#3719: tahoe_cp doesn't correctly determine when it needs to copy bytes
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 Reporter:  itamarst  |          Owner:
     Type:  defect    |         Status:  new
 Priority:  normal    |      Milestone:  undecided
Component:  unknown   |        Version:  n/a
 Keywords:            |  Launchpad Bug:
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 tahoe_cp appears to have optimizations to skip copying bytes in some
 cases.

 However, it's buggy: it does `if source.need_to_copy_bytes:` (see
 implementation of` Copier.need_to_copy_bytes`) but `need_to_copy_bytes` is
 a method! So it always comes out True, instead of calling the method and
 seeing the response.

 If that bug is fixed it hits some currently untested code paths and
 uncovers some bugs. So fixing this would also involve fixing those
 currently unreachable optimized code paths.

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3719>
Tahoe-LAFS <https://Tahoe-LAFS.org>
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