[svn-r19411] Purpose:

 Add extra test cases for Bug1975 h5diff - support recursive comparison on group when specified as an object

Description:
 Merged from hdf5 trunk (r19409)
 Additional tests for combination of group recursive and --follow-symlinks 
 with multi-linked external links with several files (same name/strucure).

Tested:
 jam, amani, heiwa

11 files changed, 468 insertions, 1 deletions

diff --git a/tools/h5diff/CMakeLists.txt b/tools/h5diff/CMakeLists.txt
index a22e0e3..924c4ec 100644
--- a/tools/h5diff/CMakeLists.txt
+++ b/tools/h5diff/CMakeLists.txt
@@ -194,6 +194,10 @@ IF (BUILD_TESTING)
       h5diff_danglelinks2.h5
       h5diff_grp_recurse1.h5
       h5diff_grp_recurse2.h5
+      h5diff_grp_recurse_ext1.h5
+      h5diff_grp_recurse_ext2-1.h5
+      h5diff_grp_recurse_ext2-2.h5
+      h5diff_grp_recurse_ext2-3.h5
       h5diff_exclude1-1.h5
       h5diff_exclude1-2.h5
       h5diff_exclude2-1.h5
@@ -304,6 +308,11 @@ SET (DANGLE_LINK_FILE1 h5diff_danglelinks1.h5)
 SET (DANGLE_LINK_FILE2 h5diff_danglelinks2.h5)
 SET (GRP_RECURSE_FILE1 h5diff_grp_recurse1.h5)
 SET (GRP_RECURSE_FILE2 h5diff_grp_recurse2.h5)
+# group recursive - same structure via external links through files 
+SET (GRP_RECURSE1_EXT h5diff_grp_recurse_ext1.h5)
+SET (GRP_RECURSE2_EXT1 h5diff_grp_recurse_ext2-1.h5)
+SET (GRP_RECURSE2_EXT2 h5diff_grp_recurse_ext2-2.h5)
+SET (GRP_RECURSE2_EXT3 h5diff_grp_recurse_ext2-3.h5)
 # same structure, same obj name with different value
 SET (EXCLUDE_FILE1_1 h5diff_exclude1-1.h5)
 SET (EXCLUDE_FILE1_2 h5diff_exclude1-2.h5)
@@ -732,6 +741,18 @@ ADD_H5_TEST (h5diff_512 -v --follow-symlinks ${GRP_RECURSE_FILE1} ${GRP_RECURSE_
 ADD_H5_TEST (h5diff_513 -v ${GRP_RECURSE_FILE1} ${GRP_RECURSE_FILE2} /slink_grp10 /slink_grp11)
 ADD_H5_TEST (h5diff_514 -v --follow-symlinks ${GRP_RECURSE_FILE1} ${GRP_RECURSE_FILE2} /slink_grp10 /slink_grp11)
 
+###############################################################################
+# Test for group recursive diff via multi-linked external links 
+# With follow-symlinks, file $GRP_RECURSE1_EXT and $GRP_RECURSE2_EXT1 should
+# be same with the external links.
+###############################################################################
+# file vs file
+ADD_H5_TEST (h5diff_515 -v ${GRP_RECURSE1_EXT} ${GRP_RECURSE2_EXT1})
+ADD_H5_TEST (h5diff_516 -v --follow-symlinks ${GRP_RECURSE1_EXT} ${GRP_RECURSE2_EXT1})
+# group vs group
+ADD_H5_TEST (h5diff_517 -v ${GRP_RECURSE1_EXT} ${GRP_RECURSE2_EXT1} /g1)
+ADD_H5_TEST (h5diff_518 -v --follow-symlinks ${GRP_RECURSE1_EXT} ${GRP_RECURSE2_EXT1} /g1)
+
 
 # ##############################################################################
 # # Exclude path (--exclude-path)
diff --git a/tools/h5diff/h5diffgentest.c b/tools/h5diff/h5diffgentest.c
index 29823e4..a3e1ef2 100644
--- a/tools/h5diff/h5diffgentest.c
+++ b/tools/h5diff/h5diffgentest.c
@@ -57,6 +57,11 @@
 #define DANGLE_LINK_FILE2   "h5diff_danglelinks2.h5"
 #define GRP_RECURSE_FILE1   "h5diff_grp_recurse1.h5"
 #define GRP_RECURSE_FILE2   "h5diff_grp_recurse2.h5"
+/* same structure via external links through files */
+#define GRP_RECURSE1_EXT    "h5diff_grp_recurse_ext1.h5"
+#define GRP_RECURSE2_EXT1   "h5diff_grp_recurse_ext2-1.h5"
+#define GRP_RECURSE2_EXT2   "h5diff_grp_recurse_ext2-2.h5"
+#define GRP_RECURSE2_EXT3   "h5diff_grp_recurse_ext2-3.h5"
 /* same structure, same obj name with different value */
 #define EXCLUDE_FILE1_1     "h5diff_exclude1-1.h5"
 #define EXCLUDE_FILE1_2     "h5diff_exclude1-2.h5"
@@ -108,6 +113,7 @@ static int test_external_links(const char *fname1, const char *fname2);
 static int test_ext2soft_links(const char *fname1, const char *fname2);
 static int test_dangle_links(const char *fname1, const char *fname2);
 static int test_group_recurse(const char *fname1, const char *fname2);
+static int test_group_recurse2();
 static int test_exclude_obj1(const char *fname1, const char *fname2);
 static int test_exclude_obj2(const char *fname1, const char *fname2);
 
@@ -160,11 +166,11 @@ int main(void)
     test_dangle_links(DANGLE_LINK_FILE1, DANGLE_LINK_FILE2);
 
     test_group_recurse(GRP_RECURSE_FILE1, GRP_RECURSE_FILE2);
+    test_group_recurse2();
 
     test_exclude_obj1(EXCLUDE_FILE1_1, EXCLUDE_FILE1_2);
     test_exclude_obj2(EXCLUDE_FILE2_1, EXCLUDE_FILE2_2);
 
-
     return 0;
 }
 
@@ -2305,6 +2311,334 @@ out:
 
 /*-------------------------------------------------------------------------
 *
+* Purpose: 
+*   For testing comparing group member objects recursively via multiple
+*   linked external links
+*
+* Programmer: Jonathan Kim (Sep 16, 2010)
+*
+*-------------------------------------------------------------------------*/
+#define GRP_R_DSETNAME1 "dset1"
+#define GRP_R_DSETNAME2 "dset2"
+static int test_group_recurse2()
+{
+    hid_t       fileid1;
+    hid_t       grp1=0, grp2;
+    hid_t       grp3=0;
+    hid_t       grp4=0;
+    hid_t       tid;
+    hid_t       dset1, dset2;
+    hid_t       datatype, dataspace;   /* handles */
+    hid_t       fileid2;
+    hid_t       fileid3;
+    hid_t       fileid4;
+    hid_t       fileid4_1;
+    hsize_t     dimsf[2];              /* dataset dimensions */
+    herr_t      status=0;
+    int data1[4][2] = {{0,0},{1,1},{2,2},{3,3}};
+    int data2[4][2] = {{0,0},{0,1},{0,2},{3,3}};
+    int         i, j;
+
+   /*-----------------------------------------------------------------------
+    * FILE 1
+    *------------------------------------------------------------------------*/
+    /*
+     * Create a new file using H5F_ACC_TRUNC access,
+     * default file creation properties, and default file
+     * access properties.
+     */
+    fileid1 = H5Fcreate(GRP_RECURSE1_EXT, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+
+   /*-----------------------------------------------------------------------
+    * Groups
+    *------------------------------------------------------------------------*/
+    grp1 = H5Gcreate2(fileid1, "/g1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp1 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE1_EXT);
+        status = FAIL;
+        goto out;
+    }
+
+    grp2 = H5Gcreate2(grp1, "g2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp2 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE1_EXT);
+        status = FAIL;
+        goto out;
+    }
+
+    grp3 = H5Gcreate2(grp2, "g3", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp3 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE1_EXT);
+        status = FAIL;
+        goto out;
+    }
+
+    grp4 = H5Gcreate2(grp3, "g4", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp4 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE1_EXT);
+        status = FAIL;
+        goto out;
+    }
+
+
+   /*-----------------------------------------------------------------------
+    * Datasets
+    *------------------------------------------------------------------------*/
+    /*
+     * Describe the size of the array and create the data space for fixed
+     * size dataset.
+     */
+    dimsf[0] = 4;
+    dimsf[1] = 2;
+    dataspace = H5Screate_simple(2, dimsf, NULL);
+
+    /*
+     * Define datatype for the data in the file.
+     * We will store little endian INT numbers.
+     */
+    datatype = H5Tcopy(H5T_NATIVE_INT);
+    status = H5Tset_order(datatype, H5T_ORDER_LE);
+
+    /*---------------
+     * dset1
+     */
+    /*
+     * Create a new dataset within the file using defined dataspace and
+     * datatype and default dataset creation properties.
+     */
+    dset1 = H5Dcreate2(fileid1, GRP_R_DSETNAME1, datatype, dataspace,
+			H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+
+    /*
+     * Write the data to the dataset using default transfer properties.
+     */
+    status = H5Dwrite(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data1);
+    H5Dclose(dset1);
+
+    /*---------------
+     * dset1
+     */
+    /*
+     * Create a new dataset within the file using defined dataspace and
+     * datatype and default dataset creation properties.
+     */
+    dset1 = H5Dcreate2(grp3, GRP_R_DSETNAME1, datatype, dataspace,
+			H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+
+    /*
+     * Write the data to the dataset using default transfer properties.
+     */
+    status = H5Dwrite(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data1);
+
+    /*---------------
+     * dset2
+     */
+    /*
+     * Create a new dataset within the fileid1 using defined dataspace and
+     * datatype and default dataset creation properties.
+     */
+    dset2 = H5Dcreate2(grp4, GRP_R_DSETNAME2, datatype, dataspace,
+			H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+
+    /*
+     * Write the data to the dataset using default transfer properties.
+     */
+    status = H5Dwrite(dset2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data2);
+
+   /*-----------------------------------------------------------------------
+    * Soft links
+    *------------------------------------------------------------------------*/
+    /*
+     * under  '/' root
+     */
+    /* link to dset1 */
+    status = H5Lcreate_soft(GRP_R_DSETNAME1, fileid1, "soft_dset1", H5P_DEFAULT, H5P_DEFAULT);
+    if (status < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Lcreate_soft failed.\n", GRP_RECURSE1_EXT);
+        status = FAIL;
+        goto out;
+    }
+
+    H5Dclose(dset1);
+    H5Dclose(dset2);
+    H5Gclose(grp1);
+    H5Gclose(grp2);
+    H5Gclose(grp3);
+    H5Gclose(grp4);
+
+   /*-----------------------------------------------------------------------
+    * FILE 2-3
+    *------------------------------------------------------------------------*/
+
+    /* crate target file */
+    fileid4 = H5Fcreate(GRP_RECURSE2_EXT3, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+
+   /*-----------------------------------------------
+    * Groups 
+    */
+    grp4 = H5Gcreate2(fileid4, "/g4", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp4 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE2_EXT3);
+        status = FAIL;
+        goto out;
+    }
+
+    /*---------------
+     * dset2
+     */
+    /*
+     * Create a new dataset within the fileid1 using defined dataspace and
+     * datatype and default dataset creation properties.
+     */
+    dset2 = H5Dcreate2(grp4, GRP_R_DSETNAME2, datatype, dataspace,
+			H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+
+    /*
+     * Write the data to the dataset using default transfer properties.
+     */
+    status = H5Dwrite(dset2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data2);
+
+    H5Gclose(grp4);
+    H5Dclose(dset2);
+
+
+   /*-----------------------------------------------------------------------
+    * FILE 2-2
+    *------------------------------------------------------------------------*/
+
+    /* crate target file */
+    fileid3 = H5Fcreate(GRP_RECURSE2_EXT2, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+
+   /*-----------------------------------------------
+    * Groups 
+    */
+    grp2 = H5Gcreate2(fileid3, "g2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp2 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE2_EXT2);
+        status = FAIL;
+        goto out;
+    }
+
+    grp3 = H5Gcreate2(grp2, "g3", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp3 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE2_EXT2);
+        status = FAIL;
+        goto out;
+    }
+
+    /*---------------
+     * dset1
+     */
+    /*
+     * Create a new dataset within the fileid1 using defined dataspace and
+     * datatype and default dataset creation properties.
+     */
+    dset1 = H5Dcreate2(grp3, GRP_R_DSETNAME1, datatype, dataspace,
+			H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+
+    /*
+     * Write the data to the dataset using default transfer properties.
+     */
+    status = H5Dwrite(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data1);
+
+   /*-----------------------------------------------
+    * extlink to  $GRP_RECURSE2_EXT3/g4
+    */
+    status = H5Lcreate_external(GRP_RECURSE2_EXT3, "/g4", fileid3, "/g2/g3/g4", H5P_DEFAULT, H5P_DEFAULT);
+    if (status < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Lcreate_external failed.\n", GRP_RECURSE2_EXT2);
+        status = FAIL;
+        goto out;
+    }
+
+    H5Dclose(dset1);
+    H5Gclose(grp2);
+    H5Gclose(grp3);
+
+   /*-----------------------------------------------------------------------
+    * FILE 2-1
+    *------------------------------------------------------------------------*/
+
+    /* crate target file */
+    fileid2 = H5Fcreate(GRP_RECURSE2_EXT1, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+
+   /*-----------------------------------------------
+    * Groups 
+    */
+    grp1 = H5Gcreate2(fileid2, "g1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if (grp1 < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Gcreate2 failed.\n", GRP_RECURSE1_EXT);
+        status = FAIL;
+        goto out;
+    }
+
+    /*---------------
+     * dset1
+     */
+    dset1 = H5Dcreate2(fileid2, GRP_R_DSETNAME1, datatype, dataspace,
+			H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+
+    /*
+     * Write the data to the dataset using default transfer properties.
+     */
+    status = H5Dwrite(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data1);
+
+   /*-----------------------------------------------------------------------
+    * Soft links
+    *------------------------------------------------------------------------*/
+    /*
+     * under  '/' root
+     */
+    /* link to dset1 */
+    status = H5Lcreate_soft(GRP_R_DSETNAME1, fileid2, "soft_dset1", H5P_DEFAULT, H5P_DEFAULT);
+    if (status < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Lcreate_soft failed.\n", GRP_RECURSE2_EXT1);
+        status = FAIL;
+        goto out;
+    }
+
+   /*-----------------------------------------------
+    * extlink to  $GRP_RECURSE2_EXT2/g2
+    */
+    status = H5Lcreate_external(GRP_RECURSE2_EXT2, "/g2", fileid2, "/g1/g2", H5P_DEFAULT, H5P_DEFAULT);
+    if (status < 0)
+    {
+        fprintf(stderr, "Error: %s> H5Lcreate_external failed.\n", GRP_RECURSE2_EXT1);
+        status = FAIL;
+        goto out;
+    }
+
+    H5Gclose(grp1);
+    H5Dclose(dset1);
+
+out:
+    /*
+     * Close/release resources.
+     */
+    H5Sclose(dataspace);
+    H5Tclose(datatype);
+    H5Fclose(fileid1);
+    H5Fclose(fileid2);
+    H5Fclose(fileid3);
+    H5Fclose(fileid4);
+
+    return status;
+}
+
+
+/*-------------------------------------------------------------------------
+*
 * Purpose: Create test files for excluding obj.
 *          Same structure, same obj names
 * Test : exclude obj with different value to verify the rest are same
diff --git a/tools/h5diff/testfiles/h5diff_515.txt b/tools/h5diff/testfiles/h5diff_515.txt
new file mode 100644
index 0000000..077d463
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_515.txt
@@ -0,0 +1,24 @@
+
+file1     file2
+---------------------------------------
+    x      x    /              
+    x      x    /dset1         
+    x      x    /g1            
+    x      x    /g1/g2         
+    x           /g1/g2/g3      
+    x           /g1/g2/g3/dset1
+    x           /g1/g2/g3/g4   
+    x           /g1/g2/g3/g4/dset2
+    x      x    /soft_dset1    
+
+group  : </> and </>
+0 differences found
+dataset: </dset1> and </dset1>
+0 differences found
+group  : </g1> and </g1>
+0 differences found
+group  : </g1/g2> and </g1/g2>
+0 differences found
+link   : </soft_dset1> and </soft_dset1>
+0 differences found
+EXIT CODE: 1
diff --git a/tools/h5diff/testfiles/h5diff_516.txt b/tools/h5diff/testfiles/h5diff_516.txt
new file mode 100644
index 0000000..32f4bd5
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_516.txt
@@ -0,0 +1,32 @@
+
+file1     file2
+---------------------------------------
+    x      x    /              
+    x      x    /dset1         
+    x      x    /g1            
+    x      x    /g1/g2         
+    x      x    /g1/g2/g3      
+    x      x    /g1/g2/g3/dset1
+    x      x    /g1/g2/g3/g4   
+    x      x    /g1/g2/g3/g4/dset2
+    x      x    /soft_dset1    
+
+group  : </> and </>
+0 differences found
+dataset: </dset1> and </dset1>
+0 differences found
+group  : </g1> and </g1>
+0 differences found
+group  : </g1/g2> and </g1/g2>
+0 differences found
+group  : </g1/g2/g3> and </g1/g2/g3>
+0 differences found
+dataset: </g1/g2/g3/dset1> and </g1/g2/g3/dset1>
+0 differences found
+group  : </g1/g2/g3/g4> and </g1/g2/g3/g4>
+0 differences found
+dataset: </g1/g2/g3/g4/dset2> and </g1/g2/g3/g4/dset2>
+0 differences found
+dataset: </soft_dset1> and </soft_dset1>
+0 differences found
+EXIT CODE: 0
diff --git a/tools/h5diff/testfiles/h5diff_517.txt b/tools/h5diff/testfiles/h5diff_517.txt
new file mode 100644
index 0000000..1b6e24f
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_517.txt
@@ -0,0 +1,15 @@
+
+group1   group2
+---------------------------------------
+    x      x                   
+    x      x    /g2            
+    x           /g2/g3         
+    x           /g2/g3/dset1   
+    x           /g2/g3/g4      
+    x           /g2/g3/g4/dset2
+
+group  : </g1> and </g1>
+0 differences found
+group  : </g1/g2> and </g1/g2>
+0 differences found
+EXIT CODE: 1
diff --git a/tools/h5diff/testfiles/h5diff_518.txt b/tools/h5diff/testfiles/h5diff_518.txt
new file mode 100644
index 0000000..f4761ad
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_518.txt
@@ -0,0 +1,23 @@
+
+group1   group2
+---------------------------------------
+    x      x                   
+    x      x    /g2            
+    x      x    /g2/g3         
+    x      x    /g2/g3/dset1   
+    x      x    /g2/g3/g4      
+    x      x    /g2/g3/g4/dset2
+
+group  : </g1> and </g1>
+0 differences found
+group  : </g1/g2> and </g1/g2>
+0 differences found
+group  : </g1/g2/g3> and </g1/g2/g3>
+0 differences found
+dataset: </g1/g2/g3/dset1> and </g1/g2/g3/dset1>
+0 differences found
+group  : </g1/g2/g3/g4> and </g1/g2/g3/g4>
+0 differences found
+dataset: </g1/g2/g3/g4/dset2> and </g1/g2/g3/g4/dset2>
+0 differences found
+EXIT CODE: 0
diff --git a/tools/h5diff/testfiles/h5diff_grp_recurse_ext1.h5 b/tools/h5diff/testfiles/h5diff_grp_recurse_ext1.h5
new file mode 100644
index 0000000..12a534a
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_grp_recurse_ext1.h5
diff --git a/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-1.h5 b/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-1.h5
new file mode 100644
index 0000000..5bb02df
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-1.h5
diff --git a/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-2.h5 b/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-2.h5
new file mode 100644
index 0000000..312543e
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-2.h5
diff --git a/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-3.h5 b/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-3.h5
new file mode 100644
index 0000000..43ad156
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_grp_recurse_ext2-3.h5
diff --git a/tools/h5diff/testh5diff.sh b/tools/h5diff/testh5diff.sh
index 71d78e7..710e430 100755
--- a/tools/h5diff/testh5diff.sh
+++ b/tools/h5diff/testh5diff.sh
@@ -54,8 +54,14 @@ FILE17=h5diff_ext2softlink_src.h5
 FILE18=h5diff_ext2softlink_trg.h5
 DANGLE_LINK_FILE1=h5diff_danglelinks1.h5
 DANGLE_LINK_FILE2=h5diff_danglelinks2.h5
+/* group recursive */
 GRP_RECURSE_FILE1=h5diff_grp_recurse1.h5
 GRP_RECURSE_FILE2=h5diff_grp_recurse2.h5
+/* group recursive - same structure via external links through files */
+GRP_RECURSE1_EXT=h5diff_grp_recurse_ext1.h5
+GRP_RECURSE2_EXT1=h5diff_grp_recurse_ext2-1.h5
+GRP_RECURSE2_EXT2=h5diff_grp_recurse_ext2-2.h5
+GRP_RECURSE2_EXT3=h5diff_grp_recurse_ext2-3.h5
 # same structure, same obj name with different value
 EXCLUDE_FILE1_1=h5diff_exclude1-1.h5
 EXCLUDE_FILE1_2=h5diff_exclude1-2.h5
@@ -733,6 +739,18 @@ TOOLTEST h5diff_512.txt -v --follow-symlinks $GRP_RECURSE_FILE1 $GRP_RECURSE_FIL
 TOOLTEST h5diff_513.txt -v $GRP_RECURSE_FILE1 $GRP_RECURSE_FILE2 /slink_grp10 /slink_grp11
 TOOLTEST h5diff_514.txt -v --follow-symlinks $GRP_RECURSE_FILE1 $GRP_RECURSE_FILE2 /slink_grp10 /slink_grp11
 
+###############################################################################
+# Test for group recursive diff via multi-linked external links 
+# With follow-symlinks, file $GRP_RECURSE1_EXT and $GRP_RECURSE2_EXT1 should
+# be same with the external links.
+###############################################################################
+# file vs file
+TOOLTEST h5diff_515.txt -v $GRP_RECURSE1_EXT $GRP_RECURSE2_EXT1
+TOOLTEST h5diff_516.txt -v --follow-symlinks $GRP_RECURSE1_EXT $GRP_RECURSE2_EXT1
+# group vs group
+TOOLTEST h5diff_517.txt -v $GRP_RECURSE1_EXT $GRP_RECURSE2_EXT1 /g1
+TOOLTEST h5diff_518.txt -v --follow-symlinks $GRP_RECURSE1_EXT $GRP_RECURSE2_EXT1 /g1
+
 # ##############################################################################
 # # Exclude objects (--exclude-path)
 # ##############################################################################