[tahoe-lafs-trac-stream] [Tahoe-LAFS] #2329: cp -r stops with an exception

[Tahoe-LAFS]

#2329: cp -r stops with an exception
-------------------------+-------------------------------------------------
     Reporter:  zooko    |      Owner:  warner
         Type:  defect   |     Status:  assigned
     Priority:  major    |  Milestone:  1.10.1
    Component:  code-    |    Version:  1.10.0
  frontend-cli           |   Keywords:  regression tahoe-cp review-needed
   Resolution:           |  easy release-blocker
Launchpad Bug:           |
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Comment (by warner):

 From a tahoe-side tree with PARENTCAP, DIRCAP=PARENTCAP/dir, and
 FILECAP=PARENTCAP/dir/file.txt, and a local (real) target directory
 "local":

 * 1.10
  * (A) `cp -r PARENTCAP/dir local/` -> `local/file.txt`
  * (B) `cp -r DIRCAP local/` -> `local/file.txt`
  * (C) `cp -r ALIAS: local/` -> `local/file.txt`
  * (D) `cp -r DIRCAP/file.txt local/` -> `local/file.txt`
  * (E) `cp -r FILECAP local/` -> "error, you must specify a destination
 filename"
  * note the target's trailing slash is optional: `local/` and `local`
 behave the same way
 * trunk (e73d76e)
  * (F) `cp -r PARENTCAP/dir local/` -> `local/dir/file.txt`
  * (G) `cp -r DIRCAP local/` -> (exception)
  * (H) `cp -r ALIAS: local/` -> (exception)
  * (I) `cp -r DIRCAP/file.txt local/` -> `local/file.txt`
  * (J) `cp -r FILECAP local/` -> "error, you must specify a destination
 filename"

 #712 fixed F to behave more like regular POSIX `/bin/cp`. I can think of
 three ways we might go with case G and H:

 * 1: `cp -r DIRCAP local/` should behave like an imaginary `cp -r DIRCAP/*
 local/` would do (this is imaginary because we have no tahoe-side globs).
 In this example, it'd create `local/file.txt`. This would match what it
 did in 1.10 (case B/C), but wouldn't match F. That'd be a shame, because
 we generally claim that "PARENTCAP/dir" and "DIRCAP" and "ALIAS:" are all
 interchangeable.

 * 2: `cp -r DIRCAP local/` would pretend that the source directory was
 named after the actual DIRCAP string (the ugly base32 representation), and
 create `local/BASE32DIRCAP/file.txt` . Ick. For H we could use the alias
 name as a target name, so it'd create `local/ALIASNAME/file.txt`, which is
 still lame but at least human-readable.

 * 3: `cp -r DIRCAP local/` would complain "you must specify a destination
 directory name", like cases E and J. This is somewhat plausible for G, and
 looks slightly weird for H.

 We don't have enough information to make case G behave like F.

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2329#comment:12>
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