hdf5_ep

[svn-r23715] Bug Fix: HDFFV-8247

Description:
  Failure to write fill values to the user's buffer when reading unallocated
  chunks from datasets that have a fill value set to H5D_FILL_VALUE_DEFAULT.
  A consequence of this was the reporting of spurious data values in h5dump
  and h5diff output.

Solution:
  Added check for fill value of H5D_FILL_VALUE_DEFAULT whenever fill value 
  setting was checked to decide whether or not to fill. This effectively
  treats H5D_FILL_VALUE_DEFAULT the same as H5D_FILL_VALUE_USER rather than
  H5D_FILL_VALUE_UNDEFINED.

Tested:
   h5committest (platypus, ostrich, jam-pp, koala) ran successfully
   (fillval test was modified to reveal and check for this error)

Note: RELEASE.txt was previously changed to reflect this fix. This
checkin was of a cleaner version of the code, but mostly to get this
full log message entered.


-This line, and those below, will be ignored--

M    H5Dchunk.c