[svn-r25140] Commit Joel's fix to this branch.

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)

H5Dchunk.c:
    fix in library code.

fillval.c:
Added test_partalloc to expose potential fill value issues.

1 files changed, 12 insertions, 5 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 7b8fc3a..43d140e 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -1731,8 +1731,9 @@ H5D__chunk_cacheable(const H5D_io_info_t *io_info, haddr_t caddr, hbool_t write_
                     /* If the fill value needs to be written then we will need
                      * to use the cache to write the fill value */
                     if(fill->fill_time == H5D_FILL_TIME_ALLOC ||
-                            (fill->fill_time == H5D_FILL_TIME_IFSET
-                            && fill_status == H5D_FILL_VALUE_USER_DEFINED))
+                            (fill->fill_time == H5D_FILL_TIME_IFSET &&
+                            (fill_status == H5D_FILL_VALUE_USER_DEFINED ||
+                             fill_status == H5D_FILL_VALUE_DEFAULT)))
                         ret_value = TRUE;
                     else
                         ret_value = FALSE;
@@ -1818,7 +1819,9 @@ H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
          * but they aren't set, set the flag to skip missing chunks.
          */
         if(fill->fill_time == H5D_FILL_TIME_NEVER ||
-                (fill->fill_time == H5D_FILL_TIME_IFSET && fill_status != H5D_FILL_VALUE_USER_DEFINED))
+                (fill->fill_time == H5D_FILL_TIME_IFSET &&
+                 fill_status != H5D_FILL_VALUE_USER_DEFINED &&
+                 fill_status != H5D_FILL_VALUE_DEFAULT))
             skip_missing_chunks = TRUE;
     }
 
@@ -2907,7 +2910,9 @@ H5D__chunk_lock(const H5D_io_info_t *io_info, H5D_chunk_ud_t *udata,
                 HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't tell if fill value defined")
 
             if(fill->fill_time == H5D_FILL_TIME_ALLOC ||
-                    (fill->fill_time == H5D_FILL_TIME_IFSET && fill_status == H5D_FILL_VALUE_USER_DEFINED)) {
+                    (fill->fill_time == H5D_FILL_TIME_IFSET &&
+                     (fill_status == H5D_FILL_VALUE_USER_DEFINED ||
+                      fill_status == H5D_FILL_VALUE_DEFAULT))) {
                 /*
                  * The chunk doesn't exist in the file.  Replicate the fill
                  * value throughout the chunk, if the fill value is defined.
@@ -3332,7 +3337,9 @@ H5D__chunk_allocate(const H5D_t *dset, hid_t dxpl_id, hbool_t full_overwrite,
      * set the "should fill" flag
      */
     if((!full_overwrite && (fill->fill_time == H5D_FILL_TIME_ALLOC ||
-            (fill->fill_time == H5D_FILL_TIME_IFSET && fill_status == H5D_FILL_VALUE_USER_DEFINED)))
+            (fill->fill_time == H5D_FILL_TIME_IFSET &&
+             (fill_status == H5D_FILL_VALUE_USER_DEFINED ||
+              fill_status == H5D_FILL_VALUE_DEFAULT))))
             || pline->nused > 0)
         should_fill = TRUE;