[svn-r17585] Purpose: Fix bug 1597

Description:
When copying a dataset  using a vlen inside a compound, the various dataset
copying callbacks would allocate a background buffer but would not use it when
converting from disk to memory, only memory to disk.  This caused an assertion
failure as compounds always need a background buffer.  These callbacks have
been modified to use the background buffer for both conversions.

Tested: jam, linew, smirom (h5committest)

4 files changed, 51 insertions, 50 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 62a3941..8788d86 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -4210,7 +4210,7 @@ H5D_chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
 
         /* Convert from source file to memory */
         H5_CHECK_OVERFLOW(udata->nelmts, uint32_t, size_t);
-        if(H5T_convert(tpath_src_mem, tid_src, tid_mem, (size_t)udata->nelmts, (size_t)0, (size_t)0, buf, NULL, udata->idx_info_dst->dxpl_id) < 0)
+        if(H5T_convert(tpath_src_mem, tid_src, tid_mem, (size_t)udata->nelmts, (size_t)0, (size_t)0, buf, bkg, udata->idx_info_dst->dxpl_id) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, H5_ITER_ERROR, "datatype conversion failed")
 
         /* Copy into another buffer, to reclaim memory later */
diff --git a/src/H5Dcompact.c b/src/H5Dcompact.c
index b52bd2c..33b92de 100644
--- a/src/H5Dcompact.c
+++ b/src/H5Dcompact.c
@@ -484,15 +484,19 @@ H5D_compact_copy(H5F_t *f_src, H5O_storage_compact_t *storage_src, H5F_t *f_dst,
 
         HDmemcpy(buf, storage_src->buf, storage_src->size);
 
+        /* allocate temporary bkg buff for data conversion */
+        if(NULL == (bkg = H5FL_BLK_MALLOC(type_conv, buf_size)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+
         /* Convert from source file to memory */
-        if(H5T_convert(tpath_src_mem, tid_src, tid_mem, nelmts, (size_t)0, (size_t)0, buf, NULL, dxpl_id) < 0)
+        if(H5T_convert(tpath_src_mem, tid_src, tid_mem, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "datatype conversion failed")
 
+        /* Copy into another buffer, to reclaim memory later */
         HDmemcpy(reclaim_buf, buf, buf_size);
 
-        /* allocate temporary bkg buff for data conversion */
-        if(NULL == (bkg = H5FL_BLK_CALLOC(type_conv, buf_size)))
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+        /* Set background buffer to all zeros */
+        HDmemset(bkg, 0, buf_size);
 
         /* Convert from memory to destination file */
         if(H5T_convert(tpath_mem_dst, tid_mem, tid_dst, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
diff --git a/src/H5Dcontig.c b/src/H5Dcontig.c
index 0ff3964..3e88be6 100644
--- a/src/H5Dcontig.c
+++ b/src/H5Dcontig.c
@@ -1396,7 +1396,7 @@ H5D_contig_copy(H5F_t *f_src, const H5O_storage_contig_t *storage_src,
         /* Perform datatype conversion, if necessary */
         if(is_vlen) {
             /* Convert from source file to memory */
-	    if(H5T_convert(tpath_src_mem, tid_src, tid_mem, nelmts, (size_t)0, (size_t)0, buf, NULL, dxpl_id) < 0)
+	    if(H5T_convert(tpath_src_mem, tid_src, tid_mem, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "datatype conversion failed")
 
             /* Copy into another buffer, to reclaim memory later */
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 08e7fa1..ab9e703 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -1935,51 +1935,48 @@ H5T_conv_struct_init(H5T_t *src, H5T_t *dst, H5T_cdata_t *cdata, hid_t dxpl_id)
         } /* end if */
     } /* end for */
 
-    /* Check if we need a background buffer */
-    if(H5T_detect_class(src, H5T_COMPOUND) == TRUE || H5T_detect_class(dst, H5T_COMPOUND) == TRUE) {
-        cdata->need_bkg = H5T_BKG_YES;
-
-        if(src_nmembs < dst_nmembs) {
-            priv->subset_info.subset = H5T_SUBSET_SRC;
-            for(i = 0; i < src_nmembs; i++) {
-                /* If any of source members doesn't have counterpart in the same
-                 * order or there's conversion between members, don't do the
-                 * optimization.
-                 */
-                if(src2dst[i] != i || (src->shared->u.compnd.memb[i].offset != dst->shared->u.compnd.memb[i].offset) || (priv->memb_path[i])->is_noop == FALSE) {
-                    priv->subset_info.subset = H5T_SUBSET_FALSE;
-                    break;
-                } /* end if */
-            } /* end for */
-            /* Compute the size of the data to be copied for each element.  It
-             * may be smaller than either src or dst if there is extra space at
-             * the end of src.
-             */
-            if(priv->subset_info.subset == H5T_SUBSET_SRC)
-                priv->subset_info.copy_size = src->shared->u.compnd.memb[src_nmembs-1].offset
-                    + src->shared->u.compnd.memb[src_nmembs-1].size;
-        } else if(dst_nmembs < src_nmembs) {
-            priv->subset_info.subset = H5T_SUBSET_DST;
-            for(i = 0; i < dst_nmembs; i++) {
-                /* If any of source members doesn't have counterpart in the same order or
-                 * there's conversion between members, don't do the optimization. */
-                if(src2dst[i] != i || (src->shared->u.compnd.memb[i].offset != dst->shared->u.compnd.memb[i].offset) || (priv->memb_path[i])->is_noop == FALSE) {
-                    priv->subset_info.subset = H5T_SUBSET_FALSE;
-                    break;
-                }
-            } /* end for */
-            /* Compute the size of the data to be copied for each element.  It
-             * may be smaller than either src or dst if there is extra space at
-             * the end of dst.
-             */
-            if(priv->subset_info.subset == H5T_SUBSET_DST)
-                priv->subset_info.copy_size = dst->shared->u.compnd.memb[dst_nmembs-1].offset
-                    + dst->shared->u.compnd.memb[dst_nmembs-1].size;
-        } else /* If the numbers of source and dest members are equal and no conversion is needed,
-                * the case should have been handled as noop earlier in H5Dio.c. */
-          ;
+    /* The compound conversion functions need a background buffer */
+    cdata->need_bkg = H5T_BKG_YES;
 
-    } /* end if */
+    if(src_nmembs < dst_nmembs) {
+        priv->subset_info.subset = H5T_SUBSET_SRC;
+        for(i = 0; i < src_nmembs; i++) {
+            /* If any of source members doesn't have counterpart in the same
+                * order or there's conversion between members, don't do the
+                * optimization.
+                */
+            if(src2dst[i] != i || (src->shared->u.compnd.memb[i].offset != dst->shared->u.compnd.memb[i].offset) || (priv->memb_path[i])->is_noop == FALSE) {
+                priv->subset_info.subset = H5T_SUBSET_FALSE;
+                break;
+            } /* end if */
+        } /* end for */
+        /* Compute the size of the data to be copied for each element.  It
+            * may be smaller than either src or dst if there is extra space at
+            * the end of src.
+            */
+        if(priv->subset_info.subset == H5T_SUBSET_SRC)
+            priv->subset_info.copy_size = src->shared->u.compnd.memb[src_nmembs-1].offset
+                + src->shared->u.compnd.memb[src_nmembs-1].size;
+    } else if(dst_nmembs < src_nmembs) {
+        priv->subset_info.subset = H5T_SUBSET_DST;
+        for(i = 0; i < dst_nmembs; i++) {
+            /* If any of source members doesn't have counterpart in the same order or
+                * there's conversion between members, don't do the optimization. */
+            if(src2dst[i] != i || (src->shared->u.compnd.memb[i].offset != dst->shared->u.compnd.memb[i].offset) || (priv->memb_path[i])->is_noop == FALSE) {
+                priv->subset_info.subset = H5T_SUBSET_FALSE;
+                break;
+            }
+        } /* end for */
+        /* Compute the size of the data to be copied for each element.  It
+            * may be smaller than either src or dst if there is extra space at
+            * the end of dst.
+            */
+        if(priv->subset_info.subset == H5T_SUBSET_DST)
+            priv->subset_info.copy_size = dst->shared->u.compnd.memb[dst_nmembs-1].offset
+                + dst->shared->u.compnd.memb[dst_nmembs-1].size;
+    } else /* If the numbers of source and dest members are equal and no conversion is needed,
+            * the case should have been handled as noop earlier in H5Dio.c. */
+        ;
 
     cdata->recalc = FALSE;