[Hackage] #269: Not having an up-to-date package list causes indexing out of bounds error

[Hackage]

#269: Not having an up-to-date package list causes indexing out of bounds error
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  Reporter:  guest               |        Owner:         
      Type:  defect              |       Status:  new    
  Priority:  low                 |    Milestone:         
 Component:  cabal-install tool  |      Version:  1.2.3.0
  Severity:  normal              |   Resolution:         
  Keywords:                      |   Difficulty:  normal 
Ghcversion:  6.8.2               |     Platform:         
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Comment (by duncan):

 I think what happens is that when we get a short download we still save it
 to disk. Then when we gunzip it it fails when gzip notices that the file
 is short. However we were still writing the file, so the bit that has been
 written out already remains. If the user does not notice the error then
 they'll continue and we end up trying to parse the truncated tar file.

 So there are three cases of bad error handling here:

   * The HTTP lib is not notifying us that the download was shorter than
 expected. Perhaps we're expected to do this manually.
   * When we decompress the .tar.gz, we should do it into a temp file and
 only overwrite the target if the decompress succeeds.
   * The tar code needs auditing to check that it handles corrupt tar files
 correctly. There's newer tar code in the hackage-server that we could test
 with and steal if necessary.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/269#comment:2>
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