[svn-r14690] Description:

    Handle comparing datasets & attributes w/variable-length strings properly.

Tested on:
    Linux/64 2.6.9 (chicago)

10 files changed, 460 insertions, 91 deletions

diff --git a/tools/h5diff/h5diffgentest.c b/tools/h5diff/h5diffgentest.c
index 735dc0f..2a95ce0 100644
--- a/tools/h5diff/h5diffgentest.c
+++ b/tools/h5diff/h5diffgentest.c
@@ -444,7 +444,7 @@ int test_types(const char *fname)
     */
     H5Lcreate_external("filename", "objname", fid1, "ext_link", H5P_DEFAULT, H5P_DEFAULT);
     H5Lregister(UD_link_class);
-    H5Lcreate_ud(fid1, "ud_link", MY_LINKCLASS, NULL, 0, H5P_DEFAULT, H5P_DEFAULT);
+    H5Lcreate_ud(fid1, "ud_link", MY_LINKCLASS, NULL, (size_t)0, H5P_DEFAULT, H5P_DEFAULT);
 
     /*-------------------------------------------------------------------------
     * Close
@@ -814,12 +814,13 @@ void write_attr_in(hid_t loc_id,
  hid_t   sid;
  hid_t   tid;
  herr_t  status;
- int     val, i, j, k, n;
+ int     val, i, j, k, l, n;
  float   f;
 
  /* create 1D attributes with dimension [2], 2 elements */
  hsize_t    dims[1]={2};
- char       buf1[2][2]= {"ab","de"};        /* string */
+ char       buf1[2][STR_SIZE]= {"ab","de"};        /* string */
+ char       *buf1a[2];                             /* VL string */
  char       buf2[2]= {1,2};                 /* bitfield, opaque */
  s_t        buf3[2]= {{1,2},{3,4}};         /* compound */
  hobj_ref_t buf4[2];                        /* reference */
@@ -832,7 +833,8 @@ void write_attr_in(hid_t loc_id,
 
  /* create 2D attributes with dimension [3][2], 6 elements */
  hsize_t    dims2[2]={3,2};
- char       buf12[6][2]= {"ab","cd","ef","gh","ij","kl"};         /* string */
+ char       buf12[3][2][STR_SIZE]= {{"ab","cd"},{"ef","gh"},{"ij","kl"}};     /* string */
+ char       *buf12a[3][2];                                               /* VL string */
  char       buf22[3][2]= {{1,2},{3,4},{5,6}};                     /* bitfield, opaque */
  s_t        buf32[6]= {{1,2},{3,4},{5,6},{7,8},{9,10},{11,12}};   /* compound */
  hobj_ref_t buf42[3][2];                                          /* reference */
@@ -844,9 +846,11 @@ void write_attr_in(hid_t loc_id,
 
  /* create 3D attributes with dimension [4][3][2], 24 elements */
  hsize_t    dims3[3]={4,3,2};
- char       buf13[24][2]= {"ab","cd","ef","gh","ij","kl","mn","pq",
- "rs","tu","vw","xz","AB","CD","EF","GH",
- "IJ","KL","MN","PQ","RS","TU","VW","XZ"};  /* string */
+ char       buf13[4][3][2][STR_SIZE]= {{{"ab","cd"},{"ef","gh"},{"ij","kl"}},
+                {{"mn","pq"},{"rs","tu"},{"vw","xz"}},
+                {{"AB","CD"},{"EF","GH"},{"IJ","KL"}},
+                {{"MN","PQ"},{"RS","TU"},{"VW","XZ"}}};  /* string */
+ char       *buf13a[4][3][2];   /* VL string */
  char       buf23[4][3][2];    /* bitfield, opaque */
  s_t        buf33[4][3][2];    /* compound */
  hobj_ref_t buf43[4][3][2];    /* reference */
@@ -871,9 +875,7 @@ void write_attr_in(hid_t loc_id,
  {
   for (i=0; i<2; i++)
    for (j=0; j<2; j++)
-   {
     buf1[i][j]='z';
-   }
  }
  /*
  buf1[2][2]= {"ab","de"};
@@ -888,10 +890,17 @@ void write_attr_in(hid_t loc_id,
 [ 1 ]          e                z
  */
  tid = H5Tcopy(H5T_C_S1);
- status  = H5Tset_size(tid, 2);
+ status  = H5Tset_size(tid, (size_t)STR_SIZE);
  write_attr(loc_id,1,dims,"string",tid,buf1);
  status = H5Tclose(tid);
 
+ for (i=0; i<2; i++)
+  buf1a[i]=buf1[i];
+ tid = H5Tcopy(H5T_C_S1);
+ status  = H5Tset_size(tid, H5T_VARIABLE);
+ write_attr(loc_id,1,dims,"VLstring",tid,buf1a);
+ status = H5Tclose(tid);
+
 /*-------------------------------------------------------------------------
  * H5T_BITFIELD
  *-------------------------------------------------------------------------
@@ -935,7 +944,7 @@ void write_attr_in(hid_t loc_id,
 [ 1 ]          2               0               2
 */
 
- tid = H5Tcreate(H5T_OPAQUE, 1);
+ tid = H5Tcreate(H5T_OPAQUE, (size_t)1);
  status = H5Tset_tag(tid, "1-byte opaque type"); /* must set this */
  write_attr(loc_id,1,dims,"opaque",tid,buf2);
  status = H5Tclose(tid);
@@ -1126,7 +1135,10 @@ position        array of </g1>  array of </g1>  difference
  */
  if (make_diffs)
  {
-  memset(buf12, 'z', sizeof buf12);
+  for (i=0; i<3; i++)
+   for (j=0; j<2; j++)
+    for (k=0; k<2; k++)
+     buf12[i][j][k]='z';
  }
 
  /*
@@ -1150,10 +1162,18 @@ position        array of </g1>  array of </g1>  difference
  */
 
  tid = H5Tcopy(H5T_C_S1);
- status  = H5Tset_size(tid, 2);
+ status  = H5Tset_size(tid, (size_t)STR_SIZE);
  write_attr(loc_id,2,dims2,"string2D",tid,buf12);
  status = H5Tclose(tid);
 
+ for (i=0; i<3; i++)
+  for (j=0; j<2; j++)
+   buf12a[i][j]=buf12[i][j];
+ tid = H5Tcopy(H5T_C_S1);
+ status  = H5Tset_size(tid, H5T_VARIABLE);
+ write_attr(loc_id,2,dims2,"VLstring2D",tid,buf12a);
+ status = H5Tclose(tid);
+
 /*-------------------------------------------------------------------------
  * H5T_BITFIELD
  *-------------------------------------------------------------------------
@@ -1201,7 +1221,7 @@ position        array of </g1>  array of </g1>  difference
 [ 2 0 ]          5               0               5
 [ 2 1 ]          6               0               6
  */
- tid = H5Tcreate(H5T_OPAQUE, 1);
+ tid = H5Tcreate(H5T_OPAQUE, (size_t)1);
  status = H5Tset_tag(tid, "1-byte opaque type"); /* must set this */
  write_attr(loc_id,2,dims2,"opaque2D",tid,buf22);
  status = H5Tclose(tid);
@@ -1288,7 +1308,6 @@ position        enum2D of </g1> enum2D of </g1> difference
  n=0;
  for (i = 0; i < 3; i++) {
   for (j = 0; j < 2; j++) {
-    int l;
     buf52[i][j].p = malloc((i + 1) * sizeof(int));
     buf52[i][j].len = i + 1;
     for (l = 0; l < i + 1; l++)
@@ -1411,7 +1430,11 @@ position        float2D of </g1> float2D of </g1> difference
 
  if (make_diffs)
  {
-  memset(buf13,'z',sizeof buf13);
+  for (i=0; i<4; i++)
+   for (j=0; j<3; j++)
+    for (k=0; k<2; k++)
+     for (l=0; l<2; l++)
+      buf13[i][j][k][l]='z';
  }
 
  /*
@@ -1472,10 +1495,19 @@ position        string3D of </g1> string3D of </g1> difference
  */
 
  tid = H5Tcopy(H5T_C_S1);
- status  = H5Tset_size(tid, 2);
+ status  = H5Tset_size(tid, (size_t)STR_SIZE);
  write_attr(loc_id,3,dims3,"string3D",tid,buf13);
  status = H5Tclose(tid);
 
+ for (i=0; i<4; i++)
+  for (j=0; j<3; j++)
+   for (k=0; k<2; k++)
+    buf13a[i][j][k]=buf13[i][j][k];
+ tid = H5Tcopy(H5T_C_S1);
+ status  = H5Tset_size(tid, H5T_VARIABLE);
+ write_attr(loc_id,3,dims3,"VLstring3D",tid,buf13a);
+ status = H5Tclose(tid);
+
 /*-------------------------------------------------------------------------
  * H5T_BITFIELD
  *-------------------------------------------------------------------------
@@ -1528,7 +1560,7 @@ position        bitfield3D of </g1> bitfield3D of </g1> difference
  * H5T_OPAQUE
  *-------------------------------------------------------------------------
  */
- tid = H5Tcreate(H5T_OPAQUE, 1);
+ tid = H5Tcreate(H5T_OPAQUE, (size_t)1);
  status = H5Tset_tag(tid, "1-byte opaque type"); /* must set this */
  write_attr(loc_id,3,dims3,"opaque3D",tid,buf23);
  status = H5Tclose(tid);
@@ -1686,7 +1718,6 @@ position        enum3D of </g1> enum3D of </g1> difference
  for (i = 0; i < 4; i++) {
   for (j = 0; j < 3; j++) {
    for (k = 0; k < 2; k++) {
-    int l;
     buf53[i][j][k].p = malloc((i + 1) * sizeof(int));
     buf53[i][j][k].len = i + 1;
     for (l = 0; l < i + 1; l++)
@@ -1821,13 +1852,14 @@ void write_dset_in(hid_t loc_id,
  hid_t   tid;
  hid_t   dcpl;
  herr_t  status;
- int     val, i, j, k, n;
+ int     val, i, j, k, l, n;
  float   f;
  int     fillvalue=2;
 
  /* create 1D attributes with dimension [2], 2 elements */
  hsize_t    dims[1]={2};
  char       buf1[2][STR_SIZE]= {"ab","de"}; /* string */
+ char       *buf1a[2];                      /* VL string */
  char       buf2[2]= {1,2};                 /* bitfield, opaque */
  s_t        buf3[2]= {{1,2},{3,4}};         /* compound */
  hobj_ref_t buf4[2];                        /* reference */
@@ -1840,7 +1872,8 @@ void write_dset_in(hid_t loc_id,
 
  /* create 2D attributes with dimension [3][2], 6 elements */
  hsize_t    dims2[2]={3,2};
- char       buf12[6][STR_SIZE]= {"ab","cd","ef","gh","ij","kl"};  /* string */
+ char       buf12[3][2][STR_SIZE]= {{"ab","cd"},{"ef","gh"},{"ij","kl"}};     /* string */
+ char       *buf12a[3][2];                                        /* VL string */
  char       buf22[3][2]= {{1,2},{3,4},{5,6}};                     /* bitfield, opaque */
  s_t        buf32[6]= {{1,2},{3,4},{5,6},{7,8},{9,10},{11,12}};   /* compound */
  hobj_ref_t buf42[3][2];                                          /* reference */
@@ -1851,9 +1884,11 @@ void write_dset_in(hid_t loc_id,
 
  /* create 3D attributes with dimension [4][3][2], 24 elements */
  hsize_t    dims3[3]={4,3,2};
- char       buf13[24][STR_SIZE]= {"ab","cd","ef","gh","ij","kl","mn","pq",
- "rs","tu","vw","xz","AB","CD","EF","GH",
- "IJ","KL","MN","PQ","RS","TU","VW","XZ"};  /* string */
+ char       buf13[4][3][2][STR_SIZE]= {{{"ab","cd"},{"ef","gh"},{"ij","kl"}},
+                {{"mn","pq"},{"rs","tu"},{"vw","xz"}},
+                {{"AB","CD"},{"EF","GH"},{"IJ","KL"}},
+                {{"MN","PQ"},{"RS","TU"},{"VW","XZ"}}};  /* string */
+ char       *buf13a[4][3][2];  /* VL string */
  char       buf23[4][3][2];    /* bitfield, opaque */
  s_t        buf33[4][3][2];    /* compound */
  hobj_ref_t buf43[4][3][2];    /* reference */
@@ -1878,17 +1913,22 @@ void write_dset_in(hid_t loc_id,
  {
   for (i=0; i<2; i++)
    for (j=0; j<2; j++)
-   {
     buf1[i][j]='z';
-   }
  }
 
 
  tid = H5Tcopy(H5T_C_S1);
- status  = H5Tset_size(tid,STR_SIZE);
+ status  = H5Tset_size(tid,(size_t)STR_SIZE);
  write_dset(loc_id,1,dims,"string",tid,buf1);
  status = H5Tclose(tid);
 
+ for (i=0; i<2; i++)
+  buf1a[i]=buf1[i];
+ tid = H5Tcopy(H5T_C_S1);
+ status  = H5Tset_size(tid, H5T_VARIABLE);
+ write_dset(loc_id,1,dims,"VLstring",tid,buf1a);
+ status = H5Tclose(tid);
+
 /*-------------------------------------------------------------------------
  * H5T_BITFIELD
  *-------------------------------------------------------------------------
@@ -1917,7 +1957,7 @@ void write_dset_in(hid_t loc_id,
   }
  }
 
- tid = H5Tcreate(H5T_OPAQUE, 1);
+ tid = H5Tcreate(H5T_OPAQUE, (size_t)1);
  status = H5Tset_tag(tid, "1-byte opaque type"); /* must set this */
  write_dset(loc_id,1,dims,"opaque",tid,buf2);
  status = H5Tclose(tid);
@@ -2051,15 +2091,26 @@ void write_dset_in(hid_t loc_id,
 
  if (make_diffs)
  {
-  memset(buf12, 'z', sizeof buf12);
+  for (i=0; i<3; i++)
+   for (j=0; j<2; j++)
+    for (k=0; k<2; k++)
+     buf12[i][j][k]='z';
  }
 
 
  tid = H5Tcopy(H5T_C_S1);
- status  = H5Tset_size(tid,STR_SIZE);
+ status  = H5Tset_size(tid,(size_t)STR_SIZE);
  write_dset(loc_id,2,dims2,"string2D",tid,buf12);
  status = H5Tclose(tid);
 
+ for (i=0; i<3; i++)
+  for (j=0; j<2; j++)
+   buf12a[i][j]=buf12[i][j];
+ tid = H5Tcopy(H5T_C_S1);
+ status  = H5Tset_size(tid, H5T_VARIABLE);
+ write_dset(loc_id,2,dims2,"VLstring2D",tid,buf12a);
+ status = H5Tclose(tid);
+
 /*-------------------------------------------------------------------------
  * H5T_BITFIELD
  *-------------------------------------------------------------------------
@@ -2079,7 +2130,7 @@ void write_dset_in(hid_t loc_id,
  * H5T_OPAQUE
  *-------------------------------------------------------------------------
  */
- tid = H5Tcreate(H5T_OPAQUE, 1);
+ tid = H5Tcreate(H5T_OPAQUE, (size_t)1);
  status = H5Tset_tag(tid, "1-byte opaque type"); /* must set this */
  write_dset(loc_id,2,dims2,"opaque2D",tid,buf22);
  status = H5Tclose(tid);
@@ -2135,8 +2186,6 @@ void write_dset_in(hid_t loc_id,
  n = 0;
  for(i = 0; i < 3; i++)
   for(j = 0; j < 2; j++) {
-    int l;
-
     buf52[i][j].p = malloc((i + 1) * sizeof(int));
     buf52[i][j].len = i + 1;
     for(l = 0; l < i + 1; l++)
@@ -2213,14 +2262,27 @@ void write_dset_in(hid_t loc_id,
 
  if (make_diffs)
  {
-  memset(buf13,'z',sizeof buf13);
+  for (i=0; i<4; i++)
+   for (j=0; j<3; j++)
+    for (k=0; k<2; k++)
+     for (l=0; l<2; l++)
+      buf13[i][j][k][l]='z';
  }
 
  tid = H5Tcopy(H5T_C_S1);
- status  = H5Tset_size(tid,STR_SIZE);
+ status  = H5Tset_size(tid,(size_t)STR_SIZE);
  write_dset(loc_id,3,dims3,"string3D",tid,buf13);
  status = H5Tclose(tid);
 
+ for (i=0; i<4; i++)
+  for (j=0; j<3; j++)
+   for (k=0; k<2; k++)
+    buf13a[i][j][k]=buf13[i][j][k];
+ tid = H5Tcopy(H5T_C_S1);
+ status  = H5Tset_size(tid, H5T_VARIABLE);
+ write_dset(loc_id,3,dims3,"VLstring3D",tid,buf13a);
+ status = H5Tclose(tid);
+
 /*-------------------------------------------------------------------------
  * H5T_BITFIELD
  *-------------------------------------------------------------------------
@@ -2246,7 +2308,7 @@ void write_dset_in(hid_t loc_id,
  * H5T_OPAQUE
  *-------------------------------------------------------------------------
  */
- tid = H5Tcreate(H5T_OPAQUE, 1);
+ tid = H5Tcreate(H5T_OPAQUE, (size_t)1);
  status = H5Tset_tag(tid, "1-byte opaque type"); /* must set this */
  write_dset(loc_id,3,dims3,"opaque3D",tid,buf23);
  status = H5Tclose(tid);
@@ -2316,8 +2378,6 @@ void write_dset_in(hid_t loc_id,
  for(i = 0; i < 4; i++)
   for(j = 0; j < 3; j++)
    for(k = 0; k < 2; k++) {
-    int l;
-
     buf53[i][j][k].p = malloc((i + 1) * sizeof(int));
     buf53[i][j][k].len = i + 1;
     for(l = 0; l < i + 1; l++)
@@ -2410,7 +2470,7 @@ void gen_datareg(hid_t fid,
  int             i;
 
  /* allocate the buffer for write the references */
- rbuf = calloc(2, sizeof(hdset_reg_ref_t));
+ rbuf = calloc((size_t)2, sizeof(hdset_reg_ref_t));
 
  /* allocate the buffer for write the data dataset */
  buf = malloc(10 * 10 * sizeof(int));
@@ -2455,7 +2515,7 @@ void gen_datareg(hid_t fid,
   coord[3][0]=2; coord[3][1]=5;
   coord[4][0]=1; coord[4][1]=7;
  }
- H5Sselect_elements(sid1,H5S_SELECT_SET,5,coord);
+ H5Sselect_elements(sid1,H5S_SELECT_SET,(size_t)5,(const hsize_t *)coord);
  H5Sget_select_npoints(sid1);
 
  /* store second dataset region */
@@ -2524,7 +2584,7 @@ int test_hyperslab(const char *fname,
   goto out;
  
  /* create a evenly divided buffer from 0 to 127  */
- buf = (char *)HDmalloc((unsigned)(nelmts * size));
+ buf = (char *)HDmalloc((size_t)(nelmts * size));
  s = 1024 * 1024 / 127;
  for(i = 0, j = 0, c = 0; i < 1024 * 1024; j++, i++) {
   if(j == s) {
diff --git a/tools/lib/h5diff_array.c b/tools/lib/h5diff_array.c
index 008b6b9..a348ca0 100644
--- a/tools/lib/h5diff_array.c
+++ b/tools/lib/h5diff_array.c
@@ -266,8 +266,6 @@ hsize_t diff_array( void *_mem1,
     size_t        size;              /* size of datum */
     unsigned char *mem1 = (unsigned char*)_mem1;
     unsigned char *mem2 = (unsigned char*)_mem2;
-    unsigned char *tmp1;
-    unsigned char *tmp2;
     hsize_t       acc[32];    /* accumulator position */
     hsize_t       pos[32];    /* matrix position */
     int           ph=1;       /* print header  */
@@ -288,23 +286,26 @@ hsize_t diff_array( void *_mem1,
     
     if(H5Tis_variable_str(m_type))
     {
-        tmp1 = ((unsigned char**)mem1)[0];
-        tmp2 = ((unsigned char**)mem2)[0];
-        nfound+=diff_datum(
-            tmp1,
-            tmp2,
-            m_type,
-            (hsize_t)0,
-            rank,
-            dims,
-            acc,
-            pos,
-            options,
-            name1,
-            name2,
-            container1_id,
-            container2_id,
-            &ph);
+        for ( i = 0; i < nelmts; i++)
+        {
+            nfound+=diff_datum(
+                ((unsigned char**)mem1)[(size_t)i],
+                ((unsigned char**)mem2)[(size_t)i],
+                m_type,
+                i,
+                rank,
+                dims,
+                acc,
+                pos,
+                options,
+                name1,
+                name2,
+                container1_id,
+                container2_id,
+                &ph);
+            if (options->n && nfound>=options->count)
+                return nfound;
+        } /* i */
     }
     
     else
@@ -515,42 +516,35 @@ hsize_t diff_datum(void       *_mem1,
     case H5T_STRING:
 
         {
-            
             H5T_str_t pad;
             char      *s;
             
-            if(H5Tis_variable_str(m_type))
-            {
-               /* mem1 is the pointer into the struct where a `char*' is stored. So we have
-                * to dereference the pointer to get the `char*' to pass to HDstrlen(). */
-                s = *(char**)mem1;
-                if(s!=NULL)
-                    size = HDstrlen(s);
-            }
-            else
-            {
-                s = (char *)mem1;
-                size = H5Tget_size(m_type);
-            }
-            
-            pad = H5Tget_strpad(m_type);
-            
+            /* Get pointer to first string to compare */
+            s = (char *)mem1;
+
             /* check for NULL pointer for string */
             if(s!=NULL)
             {
+                if(H5Tis_variable_str(m_type))
+                    size = HDstrlen(s);
+                else
+                    size = H5Tget_size(m_type);
+                
+                pad = H5Tget_strpad(m_type);
+            
                 for (u=0; u<size && (s[u] || pad!=H5T_STR_NULLTERM); u++)
                     nfound+=character_compare(
-                    mem1 + u,
-                    mem2 + u, /* offset */
-                    i,        /* index position */
-                    rank,
-                    dims,
-                    acc,
-                    pos,
-                    options,
-                    obj1,
-                    obj2,
-                    ph);
+                        mem1 + u,
+                        mem2 + u, /* offset */
+                        i,        /* index position */
+                        rank,
+                        dims,
+                        acc,
+                        pos,
+                        options,
+                        obj1,
+                        obj2,
+                        ph);
             }
                 
         }
diff --git a/tools/testfiles/h5diff_58.txt b/tools/testfiles/h5diff_58.txt
index 38d3177..b582c88 100644
--- a/tools/testfiles/h5diff_58.txt
+++ b/tools/testfiles/h5diff_58.txt
@@ -2,7 +2,7 @@
 Expected output for 'h5diff -v h5diff_dset1.h5 h5diff_dset2.h5 refreg'
 #############################
 dataset: </refreg> and </refreg>
-Referenced dataset      5904            5904
+Referenced dataset      10272            10272
 ------------------------------------------------------------
 Region blocks
 block #0           (2,2)-(7,7)           (0,0)-(2,2)
diff --git a/tools/testfiles/h5diff_70.txt b/tools/testfiles/h5diff_70.txt
index fe3e03f..bc9efbe 100644
--- a/tools/testfiles/h5diff_70.txt
+++ b/tools/testfiles/h5diff_70.txt
@@ -19,6 +19,15 @@ position        string of </>   string of </>   difference
 [ 1 ]          d                z                
 [ 1 ]          e                z                
 4 differences found
+attribute: <VLstring of </>> and <VLstring of </>>
+size:           [2]           [2]
+position        VLstring of </> VLstring of </> difference          
+------------------------------------------------------------
+[ 0 ]          a                z                
+[ 0 ]          b                z                
+[ 1 ]          d                z                
+[ 1 ]          e                z                
+4 differences found
 attribute: <bitfield of </>> and <bitfield of </>>
 size:           [2]           [2]
 position        bitfield of </> bitfield of </> difference          
@@ -99,6 +108,23 @@ position        string2D of </> string2D of </> difference
 [ 2 1 ]          k                z                
 [ 2 1 ]          l                z                
 12 differences found
+attribute: <VLstring2D of </>> and <VLstring2D of </>>
+size:           [3x2]           [3x2]
+position        VLstring2D of </> VLstring2D of </> difference          
+------------------------------------------------------------
+[ 0 0 ]          a                z                
+[ 0 0 ]          b                z                
+[ 0 1 ]          c                z                
+[ 0 1 ]          d                z                
+[ 1 0 ]          e                z                
+[ 1 0 ]          f                z                
+[ 1 1 ]          g                z                
+[ 1 1 ]          h                z                
+[ 2 0 ]          i                z                
+[ 2 0 ]          j                z                
+[ 2 1 ]          k                z                
+[ 2 1 ]          l                z                
+12 differences found
 attribute: <bitfield2D of </>> and <bitfield2D of </>>
 size:           [3x2]           [3x2]
 position        bitfield2D of </> bitfield2D of </> difference          
@@ -262,6 +288,58 @@ position        string3D of </> string3D of </> difference
 [ 3 2 1 ]          X                z                
 [ 3 2 1 ]          Z                z                
 47 differences found
+attribute: <VLstring3D of </>> and <VLstring3D of </>>
+size:           [4x3x2]           [4x3x2]
+position        VLstring3D of </> VLstring3D of </> difference          
+------------------------------------------------------------
+[ 0 0 0 ]          a                z                
+[ 0 0 0 ]          b                z                
+[ 0 0 1 ]          c                z                
+[ 0 0 1 ]          d                z                
+[ 0 1 0 ]          e                z                
+[ 0 1 0 ]          f                z                
+[ 0 1 1 ]          g                z                
+[ 0 1 1 ]          h                z                
+[ 0 2 0 ]          i                z                
+[ 0 2 0 ]          j                z                
+[ 0 2 1 ]          k                z                
+[ 0 2 1 ]          l                z                
+[ 1 0 0 ]          m                z                
+[ 1 0 0 ]          n                z                
+[ 1 0 1 ]          p                z                
+[ 1 0 1 ]          q                z                
+[ 1 1 0 ]          r                z                
+[ 1 1 0 ]          s                z                
+[ 1 1 1 ]          t                z                
+[ 1 1 1 ]          u                z                
+[ 1 2 0 ]          v                z                
+[ 1 2 0 ]          w                z                
+[ 1 2 1 ]          x                z                
+[ 2 0 0 ]          A                z                
+[ 2 0 0 ]          B                z                
+[ 2 0 1 ]          C                z                
+[ 2 0 1 ]          D                z                
+[ 2 1 0 ]          E                z                
+[ 2 1 0 ]          F                z                
+[ 2 1 1 ]          G                z                
+[ 2 1 1 ]          H                z                
+[ 2 2 0 ]          I                z                
+[ 2 2 0 ]          J                z                
+[ 2 2 1 ]          K                z                
+[ 2 2 1 ]          L                z                
+[ 3 0 0 ]          M                z                
+[ 3 0 0 ]          N                z                
+[ 3 0 1 ]          P                z                
+[ 3 0 1 ]          Q                z                
+[ 3 1 0 ]          R                z                
+[ 3 1 0 ]          S                z                
+[ 3 1 1 ]          T                z                
+[ 3 1 1 ]          U                z                
+[ 3 2 0 ]          V                z                
+[ 3 2 0 ]          W                z                
+[ 3 2 1 ]          X                z                
+[ 3 2 1 ]          Z                z                
+47 differences found
 attribute: <bitfield3D of </>> and <bitfield3D of </>>
 size:           [4x3x2]           [4x3x2]
 position        bitfield3D of </> bitfield3D of </> difference          
@@ -612,6 +690,15 @@ position        string of </dset> string of </dset> difference
 [ 1 ]          d                z                
 [ 1 ]          e                z                
 4 differences found
+attribute: <VLstring of </dset>> and <VLstring of </dset>>
+size:           [2]           [2]
+position        VLstring of </dset> VLstring of </dset> difference          
+------------------------------------------------------------
+[ 0 ]          a                z                
+[ 0 ]          b                z                
+[ 1 ]          d                z                
+[ 1 ]          e                z                
+4 differences found
 attribute: <bitfield of </dset>> and <bitfield of </dset>>
 size:           [2]           [2]
 position        bitfield of </dset> bitfield of </dset> difference          
@@ -694,6 +781,23 @@ position        string2D of </dset> string2D of </dset> difference
 [ 2 1 ]          k                z                
 [ 2 1 ]          l                z                
 12 differences found
+attribute: <VLstring2D of </dset>> and <VLstring2D of </dset>>
+size:           [3x2]           [3x2]
+position        VLstring2D of </dset> VLstring2D of </dset> difference          
+------------------------------------------------------------
+[ 0 0 ]          a                z                
+[ 0 0 ]          b                z                
+[ 0 1 ]          c                z                
+[ 0 1 ]          d                z                
+[ 1 0 ]          e                z                
+[ 1 0 ]          f                z                
+[ 1 1 ]          g                z                
+[ 1 1 ]          h                z                
+[ 2 0 ]          i                z                
+[ 2 0 ]          j                z                
+[ 2 1 ]          k                z                
+[ 2 1 ]          l                z                
+12 differences found
 attribute: <bitfield2D of </dset>> and <bitfield2D of </dset>>
 size:           [3x2]           [3x2]
 position        bitfield2D of </dset> bitfield2D of </dset> difference          
@@ -859,6 +963,58 @@ position        string3D of </dset> string3D of </dset> difference
 [ 3 2 1 ]          X                z                
 [ 3 2 1 ]          Z                z                
 47 differences found
+attribute: <VLstring3D of </dset>> and <VLstring3D of </dset>>
+size:           [4x3x2]           [4x3x2]
+position        VLstring3D of </dset> VLstring3D of </dset> difference          
+------------------------------------------------------------
+[ 0 0 0 ]          a                z                
+[ 0 0 0 ]          b                z                
+[ 0 0 1 ]          c                z                
+[ 0 0 1 ]          d                z                
+[ 0 1 0 ]          e                z                
+[ 0 1 0 ]          f                z                
+[ 0 1 1 ]          g                z                
+[ 0 1 1 ]          h                z                
+[ 0 2 0 ]          i                z                
+[ 0 2 0 ]          j                z                
+[ 0 2 1 ]          k                z                
+[ 0 2 1 ]          l                z                
+[ 1 0 0 ]          m                z                
+[ 1 0 0 ]          n                z                
+[ 1 0 1 ]          p                z                
+[ 1 0 1 ]          q                z                
+[ 1 1 0 ]          r                z                
+[ 1 1 0 ]          s                z                
+[ 1 1 1 ]          t                z                
+[ 1 1 1 ]          u                z                
+[ 1 2 0 ]          v                z                
+[ 1 2 0 ]          w                z                
+[ 1 2 1 ]          x                z                
+[ 2 0 0 ]          A                z                
+[ 2 0 0 ]          B                z                
+[ 2 0 1 ]          C                z                
+[ 2 0 1 ]          D                z                
+[ 2 1 0 ]          E                z                
+[ 2 1 0 ]          F                z                
+[ 2 1 1 ]          G                z                
+[ 2 1 1 ]          H                z                
+[ 2 2 0 ]          I                z                
+[ 2 2 0 ]          J                z                
+[ 2 2 1 ]          K                z                
+[ 2 2 1 ]          L                z                
+[ 3 0 0 ]          M                z                
+[ 3 0 0 ]          N                z                
+[ 3 0 1 ]          P                z                
+[ 3 0 1 ]          Q                z                
+[ 3 1 0 ]          R                z                
+[ 3 1 0 ]          S                z                
+[ 3 1 1 ]          T                z                
+[ 3 1 1 ]          U                z                
+[ 3 2 0 ]          V                z                
+[ 3 2 0 ]          W                z                
+[ 3 2 1 ]          X                z                
+[ 3 2 1 ]          Z                z                
+47 differences found
 attribute: <bitfield3D of </dset>> and <bitfield3D of </dset>>
 size:           [4x3x2]           [4x3x2]
 position        bitfield3D of </dset> bitfield3D of </dset> difference          
@@ -1200,7 +1356,7 @@ position        float3D of </dset> float3D of </dset> difference
 [ 3 2 0 ]          23              0               23             
 [ 3 2 1 ]          24              0               24             
 24 differences found
-456 differences found
+519 differences found
 group  : </g1> and </g1>
 0 differences found
 attribute: <string of </g1>> and <string of </g1>>
@@ -1212,6 +1368,15 @@ position        string of </g1> string of </g1> difference
 [ 1 ]          d                z                
 [ 1 ]          e                z                
 4 differences found
+attribute: <VLstring of </g1>> and <VLstring of </g1>>
+size:           [2]           [2]
+position        VLstring of </g1> VLstring of </g1> difference          
+------------------------------------------------------------
+[ 0 ]          a                z                
+[ 0 ]          b                z                
+[ 1 ]          d                z                
+[ 1 ]          e                z                
+4 differences found
 attribute: <bitfield of </g1>> and <bitfield of </g1>>
 size:           [2]           [2]
 position        bitfield of </g1> bitfield of </g1> difference          
@@ -1292,6 +1457,23 @@ position        string2D of </g1> string2D of </g1> difference
 [ 2 1 ]          k                z                
 [ 2 1 ]          l                z                
 12 differences found
+attribute: <VLstring2D of </g1>> and <VLstring2D of </g1>>
+size:           [3x2]           [3x2]
+position        VLstring2D of </g1> VLstring2D of </g1> difference          
+------------------------------------------------------------
+[ 0 0 ]          a                z                
+[ 0 0 ]          b                z                
+[ 0 1 ]          c                z                
+[ 0 1 ]          d                z                
+[ 1 0 ]          e                z                
+[ 1 0 ]          f                z                
+[ 1 1 ]          g                z                
+[ 1 1 ]          h                z                
+[ 2 0 ]          i                z                
+[ 2 0 ]          j                z                
+[ 2 1 ]          k                z                
+[ 2 1 ]          l                z                
+12 differences found
 attribute: <bitfield2D of </g1>> and <bitfield2D of </g1>>
 size:           [3x2]           [3x2]
 position        bitfield2D of </g1> bitfield2D of </g1> difference          
@@ -1455,6 +1637,58 @@ position        string3D of </g1> string3D of </g1> difference
 [ 3 2 1 ]          X                z                
 [ 3 2 1 ]          Z                z                
 47 differences found
+attribute: <VLstring3D of </g1>> and <VLstring3D of </g1>>
+size:           [4x3x2]           [4x3x2]
+position        VLstring3D of </g1> VLstring3D of </g1> difference          
+------------------------------------------------------------
+[ 0 0 0 ]          a                z                
+[ 0 0 0 ]          b                z                
+[ 0 0 1 ]          c                z                
+[ 0 0 1 ]          d                z                
+[ 0 1 0 ]          e                z                
+[ 0 1 0 ]          f                z                
+[ 0 1 1 ]          g                z                
+[ 0 1 1 ]          h                z                
+[ 0 2 0 ]          i                z                
+[ 0 2 0 ]          j                z                
+[ 0 2 1 ]          k                z                
+[ 0 2 1 ]          l                z                
+[ 1 0 0 ]          m                z                
+[ 1 0 0 ]          n                z                
+[ 1 0 1 ]          p                z                
+[ 1 0 1 ]          q                z                
+[ 1 1 0 ]          r                z                
+[ 1 1 0 ]          s                z                
+[ 1 1 1 ]          t                z                
+[ 1 1 1 ]          u                z                
+[ 1 2 0 ]          v                z                
+[ 1 2 0 ]          w                z                
+[ 1 2 1 ]          x                z                
+[ 2 0 0 ]          A                z                
+[ 2 0 0 ]          B                z                
+[ 2 0 1 ]          C                z                
+[ 2 0 1 ]          D                z                
+[ 2 1 0 ]          E                z                
+[ 2 1 0 ]          F                z                
+[ 2 1 1 ]          G                z                
+[ 2 1 1 ]          H                z                
+[ 2 2 0 ]          I                z                
+[ 2 2 0 ]          J                z                
+[ 2 2 1 ]          K                z                
+[ 2 2 1 ]          L                z                
+[ 3 0 0 ]          M                z                
+[ 3 0 0 ]          N                z                
+[ 3 0 1 ]          P                z                
+[ 3 0 1 ]          Q                z                
+[ 3 1 0 ]          R                z                
+[ 3 1 0 ]          S                z                
+[ 3 1 1 ]          T                z                
+[ 3 1 1 ]          U                z                
+[ 3 2 0 ]          V                z                
+[ 3 2 0 ]          W                z                
+[ 3 2 1 ]          X                z                
+[ 3 2 1 ]          Z                z                
+47 differences found
 attribute: <bitfield3D of </g1>> and <bitfield3D of </g1>>
 size:           [4x3x2]           [4x3x2]
 position        bitfield3D of </g1> bitfield3D of </g1> difference          
diff --git a/tools/testfiles/h5diff_80.txt b/tools/testfiles/h5diff_80.txt
index 90ee5c0..9c0bd33 100644
--- a/tools/testfiles/h5diff_80.txt
+++ b/tools/testfiles/h5diff_80.txt
@@ -8,6 +8,9 @@ file1     file2
     x      x    /dset          
     x      x    /dsetref       
     x      x    /g1            
+    x      x    /g1/VLstring   
+    x      x    /g1/VLstring2D 
+    x      x    /g1/VLstring3D 
     x      x    /g1/array      
     x      x    /g1/array2D    
     x      x    /g1/array3D    
@@ -53,6 +56,84 @@ dataset: </dsetref> and </dsetref>
 0 differences found
 group  : </g1> and </g1>
 0 differences found
+dataset: </g1/VLstring> and </g1/VLstring>
+size:           [2]           [2]
+position        VLstring        VLstring        difference          
+------------------------------------------------------------
+[ 0 ]          a                z                
+[ 0 ]          b                z                
+[ 1 ]          d                z                
+[ 1 ]          e                z                
+4 differences found
+dataset: </g1/VLstring2D> and </g1/VLstring2D>
+size:           [3x2]           [3x2]
+position        VLstring2D      VLstring2D      difference          
+------------------------------------------------------------
+[ 0 0 ]          a                z                
+[ 0 0 ]          b                z                
+[ 0 1 ]          c                z                
+[ 0 1 ]          d                z                
+[ 1 0 ]          e                z                
+[ 1 0 ]          f                z                
+[ 1 1 ]          g                z                
+[ 1 1 ]          h                z                
+[ 2 0 ]          i                z                
+[ 2 0 ]          j                z                
+[ 2 1 ]          k                z                
+[ 2 1 ]          l                z                
+12 differences found
+dataset: </g1/VLstring3D> and </g1/VLstring3D>
+size:           [4x3x2]           [4x3x2]
+position        VLstring3D      VLstring3D      difference          
+------------------------------------------------------------
+[ 0 0 0 ]          a                z                
+[ 0 0 0 ]          b                z                
+[ 0 0 1 ]          c                z                
+[ 0 0 1 ]          d                z                
+[ 0 1 0 ]          e                z                
+[ 0 1 0 ]          f                z                
+[ 0 1 1 ]          g                z                
+[ 0 1 1 ]          h                z                
+[ 0 2 0 ]          i                z                
+[ 0 2 0 ]          j                z                
+[ 0 2 1 ]          k                z                
+[ 0 2 1 ]          l                z                
+[ 1 0 0 ]          m                z                
+[ 1 0 0 ]          n                z                
+[ 1 0 1 ]          p                z                
+[ 1 0 1 ]          q                z                
+[ 1 1 0 ]          r                z                
+[ 1 1 0 ]          s                z                
+[ 1 1 1 ]          t                z                
+[ 1 1 1 ]          u                z                
+[ 1 2 0 ]          v                z                
+[ 1 2 0 ]          w                z                
+[ 1 2 1 ]          x                z                
+[ 2 0 0 ]          A                z                
+[ 2 0 0 ]          B                z                
+[ 2 0 1 ]          C                z                
+[ 2 0 1 ]          D                z                
+[ 2 1 0 ]          E                z                
+[ 2 1 0 ]          F                z                
+[ 2 1 1 ]          G                z                
+[ 2 1 1 ]          H                z                
+[ 2 2 0 ]          I                z                
+[ 2 2 0 ]          J                z                
+[ 2 2 1 ]          K                z                
+[ 2 2 1 ]          L                z                
+[ 3 0 0 ]          M                z                
+[ 3 0 0 ]          N                z                
+[ 3 0 1 ]          P                z                
+[ 3 0 1 ]          Q                z                
+[ 3 1 0 ]          R                z                
+[ 3 1 0 ]          S                z                
+[ 3 1 1 ]          T                z                
+[ 3 1 1 ]          U                z                
+[ 3 2 0 ]          V                z                
+[ 3 2 0 ]          W                z                
+[ 3 2 1 ]          X                z                
+[ 3 2 1 ]          Z                z                
+47 differences found
 dataset: </g1/array> and </g1/array>
 size:           [2]           [2]
 position        array           array           difference          
@@ -776,7 +857,7 @@ position        vlen3D          vlen3D          difference
 [ 3 2 1 ]          59              0               59             
 59 differences found
 dataset: </refreg> and </refreg>
-Referenced dataset      5904            5904
+Referenced dataset      10272            10272
 ------------------------------------------------------------
 Region blocks
 block #0           (2,2)-(7,7)           (0,0)-(2,2)
diff --git a/tools/testfiles/h5diff_attr1.h5 b/tools/testfiles/h5diff_attr1.h5
index e261486..c44066b 100644
--- a/tools/testfiles/h5diff_attr1.h5
+++ b/tools/testfiles/h5diff_attr1.h5
diff --git a/tools/testfiles/h5diff_attr2.h5 b/tools/testfiles/h5diff_attr2.h5
index 0a59fc5..5de3303 100644
--- a/tools/testfiles/h5diff_attr2.h5
+++ b/tools/testfiles/h5diff_attr2.h5
diff --git a/tools/testfiles/h5diff_basic2.h5 b/tools/testfiles/h5diff_basic2.h5
index 209485f..ad45cc0 100644
--- a/tools/testfiles/h5diff_basic2.h5
+++ b/tools/testfiles/h5diff_basic2.h5
diff --git a/tools/testfiles/h5diff_dset1.h5 b/tools/testfiles/h5diff_dset1.h5
index 3f853be..ab6b96f 100644
--- a/tools/testfiles/h5diff_dset1.h5
+++ b/tools/testfiles/h5diff_dset1.h5
diff --git a/tools/testfiles/h5diff_dset2.h5 b/tools/testfiles/h5diff_dset2.h5
index 1f14d29..3db0c8e 100644
--- a/tools/testfiles/h5diff_dset2.h5
+++ b/tools/testfiles/h5diff_dset2.h5