[Bug-tar] spurious warning in short_read

[Samuel Thibault]

Hello,

Since at least tar 1.22, there is an additional warning in short_read:

  if (left && left % BLOCKSIZE == 0
      && verbose_option
      && record_start_block == 0 && status != 0)
    {
      unsigned long rsize = status / BLOCKSIZE;
      WARN ((0, 0,
             ngettext ("Record size = %lu block",
                       "Record size = %lu blocks",
                       rsize),
             rsize));
    }

Why is that done?  Reads on pipes typically return short reads, and
these are typically aligned on page size, and thus record_size (10240
here) % BLOCKSIZE is typically 0...

The problem is that this makes the testsuite fail in comprec.at, where
verbose_option is set to 1 and thus the warning comes in the way while
the test actually succeeds.

Samuel