patch: unzip succeeds with CRC errors

[Paul Fox]

me:
 > > i'm going to commit the two line change i have now since i believe
 > > it's a necessary first step, no matter what else is done.

rich felker wrote:
 > No it's not. The correct fix is to set an error flag, then check the
 > error flag on exit and exit with failure status if it's set. Exiting
 > as soon as a CRC failure is detected is a regression.

correctly reporting failure hardly seems like a "regression" to
me, though granted, you're probably coming at this from an
interactive use point of view ("dammit, i want as many files as i
can get"), and i'm coming at it from the point of view of
scriptability ("it failed.  stop now").

have you looked at the code since this topic came up?  (the other
day you said that you had not.)  currently unzip dies immediately for
every error condition _except_ CRC failure:  write failures,
mismatched node types, unsupported compression methods, failure
to read zip headers (which might be the result of a previous
corrupted archive member which would have reported a CRC error),
etc.  all i'm proposing is adding "CRC failure" to the list of
conditions which cause immediate exit.

i'll hold off on committing this, but i'm also not going to take
on the "make unzip tolerant of various mid-stream errors" task,
with the requisite testing.

paul
=---------------------
 paul fox, pgf at brightstareng.com