[svn-r17119] Bug fix #1513. Reading an empty attribute caused seg fault. The flag "initialized" in

the attribute structure wan't set correctly.  It caused some confusion in H5A_read.  This
flag was actually redundant because the library can alwasy check if the data buffer is
present.  To fix it, I removed the "initialized" flag in the attribute structure and let
H5A_read check the data buffer.

Tested on jam, smirom, and linex.
 

5 files changed, 63 insertions, 23 deletions

diff --git a/src/H5A.c b/src/H5A.c
index 325f7be..d359130 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -436,9 +436,6 @@ H5A_create(const H5G_loc_t *loc, const char *name, const H5T_t *type,
         if(H5S_set_latest_version(attr->shared->ds) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set latest version of dataspace")
 
-    /* Mark it initially set to initialized */
-    attr->shared->initialized = TRUE; /*for now, set to false later*/
-
     /* Copy the object header information */
     if(H5O_loc_copy(&(attr->oloc), loc->oloc, H5_COPY_DEEP) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to copy entry")
@@ -498,9 +495,6 @@ H5A_create(const H5G_loc_t *loc, const char *name, const H5T_t *type,
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
         HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
 
-    /* Now it's safe to say it's uninitialized */
-    attr->shared->initialized = FALSE;
-
 done:
     /* Cleanup on failure */
     if(ret_value < 0 && attr && H5A_close(attr) < 0)
@@ -550,7 +544,6 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t UNUSED aapl_id)
     /* Read in attribute from object header */
     if(NULL == (attr = H5O_attr_open_by_name(loc.oloc, attr_name, H5AC_ind_dxpl_id)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to load attribute info from object header")
-    attr->shared->initialized = TRUE;
 
     /* Finish initializing attribute */
     if(H5A_open_common(&loc, attr) < 0)
@@ -805,7 +798,6 @@ H5A_open_by_idx(const H5G_loc_t *loc, const char *obj_name, H5_index_t idx_type,
     /* Read in attribute from object header */
     if(NULL == (attr = H5O_attr_open_by_idx(obj_loc.oloc, idx_type, order, n, dxpl_id)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "unable to load attribute info from object header")
-    attr->shared->initialized = TRUE;
 
     /* Finish initializing attribute */
     if(H5A_open_common(&obj_loc, attr) < 0)
@@ -871,7 +863,6 @@ H5A_open_by_name(const H5G_loc_t *loc, const char *obj_name, const char *attr_na
     /* Read in attribute from object header */
     if(NULL == (attr = H5O_attr_open_by_name(obj_loc.oloc, attr_name, dxpl_id)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, NULL, "unable to load attribute info from object header")
-    attr->shared->initialized = TRUE;
 
     /* Finish initializing attribute */
     if(H5A_open_common(loc, attr) < 0)
@@ -1036,9 +1027,6 @@ H5A_write(H5A_t *attr, const H5T_t *mem_type, const void *buf, hid_t dxpl_id)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to modify attribute")
     } /* end if */
 
-    /* Indicate the the attribute doesn't need fill-values */
-    attr->shared->initialized = TRUE;
-
 done:
     /* Release resources */
     if(src_id >= 0)
@@ -1144,7 +1132,7 @@ H5A_read(const H5A_t *attr, const H5T_t *mem_type, void *buf, hid_t dxpl_id)
         dst_type_size = H5T_GET_SIZE(mem_type);
 
         /* Check if the attribute has any data yet, if not, fill with zeroes */
-        if(attr->obj_opened && !attr->shared->initialized)
+        if(attr->obj_opened && !attr->shared->data)
             HDmemset(buf, 0, (dst_type_size * nelmts));
         else {  /* Attribute exists and has a value */
             /* Convert memory buffer into disk buffer */
diff --git a/src/H5Aint.c b/src/H5Aint.c
index 2ac17fa..475239a 100644
--- a/src/H5Aint.c
+++ b/src/H5Aint.c
@@ -1022,9 +1022,6 @@ H5A_attr_copy_file(const H5A_t *attr_src, H5F_t *file_dst, hbool_t *recompute_si
     if(H5A_set_version(file_dst, attr_dst) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, NULL, "unable to update attribute version")
 
-    /* Indicate that the fill values aren't to be written out */
-    attr_dst->shared->initialized = TRUE;
-
     /* Set return value */
     ret_value = attr_dst;
 
diff --git a/src/H5Apkg.h b/src/H5Apkg.h
index 3c62635..4216fa3 100644
--- a/src/H5Apkg.h
+++ b/src/H5Apkg.h
@@ -75,7 +75,6 @@
 /* Define the shared attribute structure */
 typedef struct H5A_shared_t {
     unsigned    version;    /* Version to encode attribute with */
-    hbool_t     initialized;/* Indicate whether the attribute has been modified */
 
     char        *name;      /* Attribute's name */
     H5T_cset_t  encoding;   /* Character encoding of attribute name */
diff --git a/src/H5Oattr.c b/src/H5Oattr.c
index 27b9d5e..1e85c69 100644
--- a/src/H5Oattr.c
+++ b/src/H5Oattr.c
@@ -226,9 +226,6 @@ H5O_attr_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, unsigned UNUSED mesg_fl
         HDmemcpy(attr->shared->data, p, attr->shared->data_size);
     } /* end if */
 
-    /* Indicate that the fill values aren't to be written out */
-    attr->shared->initialized = 1;
-
     /* Increment the reference count for this object header message in cache(compact
        storage) or for the object from dense storage. */
     attr->shared->nrefs++;
@@ -805,9 +802,6 @@ H5O_attr_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg, FILE * stream, int in
             "Character Set of Name:",
             s);
     HDfprintf(stream, "%*s%-*s %t\n", indent, "", fwidth,
-	    "Initialized:",
-	    mesg->shared->initialized);
-    HDfprintf(stream, "%*s%-*s %t\n", indent, "", fwidth,
 	    "Object opened:",
 	    mesg->obj_opened);
     HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
diff --git a/test/tattr.c b/test/tattr.c
index 4b130e6..5eb378f 100644
--- a/test/tattr.c
+++ b/test/tattr.c
@@ -10145,6 +10145,66 @@ test_attr_bug5(hid_t fcpl, hid_t fapl)
 
 /****************************************************************
 **
+**  test_attr_bug6(): Test basic H5A (attribute) code.
+**      Tests if reading an empty attribute is OK.
+**
+****************************************************************/
+static void
+test_attr_bug6(hid_t fcpl, hid_t fapl)
+{
+    hid_t   fid;            /* File ID */
+    hid_t   gid;            /* Group ID */
+    hid_t   aid1, aid2;     /* Attribute IDs */
+    hid_t   sid;            /* Dataspace ID */
+    hsize_t dims[1] = {5};  /* Attribute dimensions */
+    int     intar[5];       /* Data reading buffer */
+    herr_t  ret;            /* Generic return status */
+
+    /* Output message about test being performed */
+    MESSAGE(5, ("Testing that empty attribute can be read\n"));
+
+    /* Create file */
+    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Open root group */
+    gid = H5Gopen2(fid, "/", H5P_DEFAULT);
+    CHECK(gid, FAIL, "H5Gcreate2");
+
+    /* Create dataspace */
+    sid = H5Screate_simple(1, dims, NULL);
+    CHECK(sid, FAIL, "H5Screate_simple");
+
+    /* Create attribute on group */
+    aid1 = H5Acreate2(gid, "attr", H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(aid1, FAIL, "H5Acreate2");
+
+    ret = H5Aclose(aid1);
+    CHECK(ret, FAIL, "H5Aclose");
+
+    /* Open the attribute again */
+    aid2 = H5Aopen_name(gid, "attr");
+    CHECK(aid2, FAIL, "H5Aopen_name");
+
+    ret = H5Aread(aid2, H5T_NATIVE_INT, intar);
+    CHECK(ret, FAIL, "H5Aread");
+
+    /* Close IDs */
+    ret = H5Aclose(aid2);
+    CHECK(ret, FAIL, "H5Aclose");
+
+    ret = H5Gclose(gid);
+    CHECK(ret, FAIL, "H5Gclose");
+
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+    ret = H5Sclose(sid);
+    CHECK(ret, FAIL, "H5Sclose");
+}
+
+/****************************************************************
+**
 **  test_attr(): Main H5A (attribute) testing routine.
 **
 ****************************************************************/
@@ -10288,6 +10348,7 @@ test_attr(void)
                 test_attr_bug3(my_fcpl, my_fapl);               /* Test "self referential" attributes */
                 test_attr_bug4(my_fcpl, my_fapl);               /* Test attributes on named datatypes */
                 test_attr_bug5(my_fcpl, my_fapl);               /* Test opening/closing attributes through different file handles */
+                test_attr_bug6(my_fcpl, my_fapl);               /* Test reading empty attribute */ 
             } /* end for */
         } /* end if */
         else {
@@ -10311,6 +10372,7 @@ test_attr(void)
             test_attr_bug3(fcpl, my_fapl);                      /* Test "self referential" attributes */
             test_attr_bug4(fcpl, my_fapl);                      /* Test attributes on named datatypes */
             test_attr_bug5(fcpl, my_fapl);                      /* Test opening/closing attributes through different file handles */
+            test_attr_bug6(fcpl, my_fapl);                      /* Test reading empty attribute */ 
         } /* end else */
     } /* end for */