Merge pull request #1348 in HDFFV/hdf5 from ~SONGYULU/hdf5_ray:bugfix/HDFFV-10635-hdf5-library-segmentation-fault to develop

* commit '3e8599591504c95d8a97100b9546174f6132dc97':
  HDFFV-10635: Some minor changes to the test case and the comments in the library.
  HDFFV-10635: add a test case.
  HDFFV-10635: Allowing to write the same variable-length element more than once.

2 files changed, 111 insertions, 3 deletions

diff --git a/src/H5HG.c b/src/H5HG.c
index b9d8dc3..df1c82d 100644
--- a/src/H5HG.c
+++ b/src/H5HG.c
@@ -785,7 +785,14 @@ H5HG_remove (H5F_t *f, H5HG_t *hobj)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect global heap")
 
     HDassert(hobj->idx < heap->nused);
-    HDassert(heap->obj[hobj->idx].begin);
+    
+    /* When the application selects the same location to rewrite the VL element by using H5Sselect_elements,
+     * it can happen that the entry has been removed by first rewrite.  Here we simply skip the removal of
+     * the entry and let the second rewrite happen (see HDFFV-10635).  In the future, it'd be nice to handle
+     * this situation in H5T_conv_vlen in H5Tconv.c instead of this level (HDFFV-10648). */
+    if(heap->obj[hobj->idx].nrefs == 0 && heap->obj[hobj->idx].size == 0 && !heap->obj[hobj->idx].begin)
+        HGOTO_DONE(ret_value)
+        
     obj_start = heap->obj[hobj->idx].begin;
     /* Include object header size */
     need = H5HG_ALIGN(heap->obj[hobj->idx].size) + H5HG_SIZEOF_OBJHDR(f);
diff --git a/test/tvlstr.c b/test/tvlstr.c
index 3315d68..68d1070 100644
--- a/test/tvlstr.c
+++ b/test/tvlstr.c
@@ -23,12 +23,16 @@
 
 #define DATAFILE   "tvlstr.h5"
 #define DATAFILE2  "tvlstr2.h5"
+#define DATAFILE3  "sel2el.h5"
+
+#define DATASET    "1Darray"
 
 /* 1-D dataset with fixed dimensions */
 #define SPACE1_RANK    1
 #define SPACE1_DIM1    4
+#define NUMP           4
 
-#define VLSTR_TYPE      "vl_string_type"
+#define VLSTR_TYPE  "vl_string_type"
 
 /* Definitions for the VL re-writing test */
 #define REWRITE_NDATASETS       32
@@ -846,6 +850,101 @@ static void test_vl_rewrite(void)
 } /* end test_vl_rewrite() */
 
 /****************************************************************
+ **
+ **  test_write_same_element():
+ **      Tests writing to the same element of VL string using
+ **      H5Sselect_element.
+ **
+ ****************************************************************/
+static void test_write_same_element(void)
+{
+    hid_t   file1, dataset1;
+    hid_t   mspace, fspace, dtype;
+    hsize_t fdim[] = {SPACE1_DIM1};
+    char *val[SPACE1_DIM1] = {"But", "reuniting", "is a", "great joy"};
+    hsize_t marray[] = {NUMP};
+    hsize_t coord[SPACE1_RANK][NUMP];
+    herr_t ret;
+
+    char *wdata[SPACE1_DIM1] = {"Parting", "is such a", "sweet", "sorrow."};
+
+    file1 = H5Fcreate(DATAFILE3, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(file1, FAIL, "H5Fcreate");
+
+    dtype = H5Tcopy(H5T_C_S1);
+    CHECK(dtype, FAIL, "H5Tcopy");
+
+    ret = H5Tset_size(dtype, H5T_VARIABLE);
+    CHECK(ret, FAIL, "H5Tset_size");
+
+    fspace = H5Screate_simple(SPACE1_RANK, fdim, NULL);
+    CHECK(fspace, FAIL, "H5Screate_simple");
+
+    dataset1 = H5Dcreate(file1, DATASET, dtype, fspace, H5P_DEFAULT,
+                          H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(dataset1, FAIL, "H5Dcreate");
+
+    ret = H5Dwrite(dataset1, dtype, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata);
+    CHECK(ret, FAIL, "H5Dwrite");
+
+    ret = H5Dclose(dataset1);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    ret = H5Tclose(dtype);
+    CHECK(ret, FAIL, "H5Tclose");
+
+    ret = H5Sclose(fspace);
+    CHECK(ret, FAIL, "H5Sclose");
+
+    ret = H5Fclose(file1);
+    CHECK(ret, FAIL, "H5Fclose");
+
+    /*
+     * Open the file.  Select the same points, write values to those point locations.
+     */
+    file1 = H5Fopen(DATAFILE3, H5F_ACC_RDWR, H5P_DEFAULT);
+    CHECK(file1, FAIL, "H5Fopen");
+
+    dataset1 = H5Dopen(file1, DATASET, H5P_DEFAULT);
+    CHECK(dataset1, FAIL, "H5Dopen");
+
+    fspace = H5Dget_space(dataset1);
+    CHECK(fspace, FAIL, "H5Dget_space");
+
+    dtype = H5Dget_type(dataset1);
+    CHECK(dtype, FAIL, "H5Dget_type");
+
+    mspace = H5Screate_simple(1, marray, NULL);
+    CHECK(mspace, FAIL, "H5Screate_simple");
+
+    coord[0][0] = 0;
+    coord[0][1] = 2;
+    coord[0][2] = 2;
+    coord[0][3] = 0;
+
+    ret = H5Sselect_elements(fspace, H5S_SELECT_SET, NUMP, (const hsize_t *)&coord);
+    CHECK(ret, FAIL, "H5Sselect_elements");
+
+    ret = H5Dwrite(dataset1, dtype, mspace, fspace, H5P_DEFAULT, val);
+    CHECK(ret, FAIL, "H5Dwrite");
+
+    ret = H5Tclose(dtype);
+    CHECK(ret, FAIL, "H5Tclose");
+
+    ret = H5Dclose(dataset1);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    ret = H5Sclose(fspace);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    ret = H5Sclose(mspace);
+    CHECK(ret, FAIL, "H5Sclose");
+
+    ret = H5Fclose(file1);
+    CHECK(ret, FAIL, "H5Fclose");
+} /* test_write_same_element */
+
+/****************************************************************
 **
 **  test_vlstrings(): Main VL string testing routine.
 **
@@ -869,9 +968,10 @@ test_vlstrings(void)
 
     /* Test writing VL datasets in files with lots of unlinking */
     test_vl_rewrite();
+    /* Test writing to the same element more than once using H5Sselect_elements */
+    test_write_same_element();
 }   /* test_vlstrings() */
 
-
 /*-------------------------------------------------------------------------
  * Function:    cleanup_vlstrings
  *
@@ -891,5 +991,6 @@ cleanup_vlstrings(void)
 {
     HDremove(DATAFILE);
     HDremove(DATAFILE2);
+    HDremove(DATAFILE3);
 }