1 8 Merges from develop (#432)

* Update supported platforms

* Merge PR#3 changes from develop

* # WARNING: head commit changed in the meantime

Merge gcc 10 diagnostics option from develop

Merge CMake changes from develop
Merge warnings from develop
Merge #318 OSX changes from develop
Merge tools changes from develop
Merge test macros from develop

* Format updates

* Fix missing semicolon and format fix

* Format update

* Correct actions, remove java option

* Update autotools build files

* Add testfiles

* Fix configure issue with make flags

* Init fapls to default

* Update generated files and fix h5repack id closure

* update format

* Merges from develop

#358 patches from vtk
#361 fix header guard spelling

* Merges from develop

#340 clang -Wformat-security warnings
#360 Fixed uninitialized warnings
header guard underscore cleanup
whitespace cleanup
tools sync

* format alignment

* initialize vars

* revert H5private change

* Merge #380 from develop

16 files changed, 232 insertions, 59 deletions

diff --git a/tools/h5diff/CMakeTests.cmake b/tools/h5diff/CMakeTests.cmake
index ca321a4..97d92b8 100644
--- a/tools/h5diff/CMakeTests.cmake
+++ b/tools/h5diff/CMakeTests.cmake
@@ -872,6 +872,8 @@
           h5diff_800.out.err
           h5diff_801.out
           h5diff_801.out.err
+          h5diff_830.out
+          h5diff_830.out.err
           h5diff_8625.out
           h5diff_8625.out.err
           h5diff_8639.out
@@ -1487,6 +1489,11 @@ ADD_H5_TEST (h5diff_646 1 -v --use-system-epsilon -p 0.05 ${FILE1} ${FILE2} /g1/
 ADD_H5_TEST (h5diff_800 1 -v ${FILE7} ${FILE8} /g1/array /g1/array)
 ADD_H5_TEST (h5diff_801 1 -v ${FILE7} ${FILE8A} /g1/array /g1/array)
 
+# ##############################################################################
+# # dataset subsets
+# ##############################################################################
+#TRILABS_227 ADD_H5_TEST (h5diff_830 1 --enable-error-stack -v ${FILE7} ${FILE8} /g1/array3D[0,0,0;2,2,1;2,2,2;] /g1/array3D[0,0,0;2,2,1;2,2,2;])
+
 ##############################################################################
 ###    P L U G I N  T E S T S
 ##############################################################################
diff --git a/tools/h5diff/h5diff_common.c b/tools/h5diff/h5diff_common.c
index a34ebe9..01eaf86 100644
--- a/tools/h5diff/h5diff_common.c
+++ b/tools/h5diff/h5diff_common.c
@@ -70,7 +70,6 @@ check_options(diff_opt_t *opts)
     }
 }
 
-#if TRILABS_227
 /*-------------------------------------------------------------------------
  * Function:    parse_hsize_list
  *
@@ -186,7 +185,6 @@ parse_subset_params(const char *dset)
 
     return s;
 }
-#endif
 
 /*-------------------------------------------------------------------------
  * Function: parse_command_line
@@ -442,11 +440,9 @@ parse_command_line(int argc, const char *argv[], const char **fname1, const char
      * TRILABS_227 is complete except for an issue with printing indices
      * the following calls will enable subsetting
      */
-#if TRILABS_227
     opts->sset[0] = parse_subset_params(*objname1);
 
     opts->sset[1] = parse_subset_params(*objname2);
-#endif
 
     H5TOOLS_ENDDEBUG("");
 }
@@ -766,19 +762,27 @@ usage(void)
     /*
      * TRILABS_227 is complete except for an issue with printing indices
      * the following will be needed for subsetting
+     */
     PRINTVALSTREAM(rawoutstream, " Subsetting options:\n");
-    PRINTVALSTREAM(rawoutstream, "  Subsetting is available by using the fcompact form of subsetting, as
-    follows:\n"); PRINTVALSTREAM(rawoutstream, "    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]\n");
-    PRINTVALSTREAM(rawoutstream, "  It is not required to use all parameters, but until the last parameter
-    value used,\n"); PRINTVALSTREAM(rawoutstream, "  all of the semicolons (;) are required, even when a
-    parameter value is not specified. Example:\n"); PRINTVALSTREAM(rawoutstream, "    obj1
-    /foo/mydataset[START;;COUNT;BLOCK]\n"); PRINTVALSTREAM(rawoutstream, "    obj1 /foo/mydataset[START]\n");
-    PRINTVALSTREAM(rawoutstream, "  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1
-    in\n"); PRINTVALSTREAM(rawoutstream, "  each dimension. START is optional and will default to 0 in each
-    dimension.\n"); PRINTVALSTREAM(rawoutstream, "  Each of START, STRIDE, COUNT, and BLOCK must be a
-    comma-separated list of integers with\n"); PRINTVALSTREAM(rawoutstream, "  one integer for each dimension
-    of the dataset.\n"); PRINTVALSTREAM(rawoutstream, "\n");
-   */
+    PRINTVALSTREAM(rawoutstream,
+                   "  Subsetting is available by using the fcompact form of subsetting, as follows:\n");
+    PRINTVALSTREAM(rawoutstream, "    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "  It is not required to use all parameters, but until the last parameter value used,\n");
+    PRINTVALSTREAM(
+        rawoutstream,
+        "  all of the semicolons (;) are required, even when a parameter value is not specified. Example:\n");
+    PRINTVALSTREAM(rawoutstream, "    obj1 /foo/mydataset[START;;COUNT;BLOCK]\n");
+    PRINTVALSTREAM(rawoutstream, "    obj1 /foo/mydataset[START]\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "  each dimension. START is optional and will default to 0 in each dimension.\n");
+    PRINTVALSTREAM(
+        rawoutstream,
+        "  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with\n");
+    PRINTVALSTREAM(rawoutstream, "  one integer for each dimension of the dataset.\n");
+    PRINTVALSTREAM(rawoutstream, "\n");
     PRINTVALSTREAM(rawoutstream, " Exit code:\n");
     PRINTVALSTREAM(rawoutstream, "  0 if no differences, 1 if differences found, 2 if error\n");
     PRINTVALSTREAM(rawoutstream, "\n");
diff --git a/tools/h5diff/h5diff_common.h b/tools/h5diff/h5diff_common.h
index 6594478..83f4255 100644
--- a/tools/h5diff/h5diff_common.h
+++ b/tools/h5diff/h5diff_common.h
@@ -11,8 +11,8 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#ifndef H5DIFFCOMMON_H__
-#define H5DIFFCOMMON_H__
+#ifndef H5DIFFCOMMON_H
+#define H5DIFFCOMMON_H
 
 #include "h5tools.h"
 /* Name of tool */
@@ -32,4 +32,4 @@ void print_info(diff_opt_t *opts);
 }
 #endif
 
-#endif /* H5DIFFCOMMON_H__ */
+#endif /* H5DIFFCOMMON_H */
diff --git a/tools/h5diff/h5diff_plugin.sh.in b/tools/h5diff/h5diff_plugin.sh.in
index 832981d..076ca74 100644
--- a/tools/h5diff/h5diff_plugin.sh.in
+++ b/tools/h5diff/h5diff_plugin.sh.in
@@ -217,19 +217,21 @@ TOOLTEST() {
     # Run test.
     TESTING $H5DIFF $@
     (
-    #echo "#############################"
-    #echo "Expected output for '$H5DIFF $@'"
-    #echo "#############################"
-    cd $TESTDIR
-    eval $ENVCMD $RUNCMD $H5DIFF_BIN "$@"
+        #echo "#############################"
+        #echo "Expected output for '$H5DIFF $@'"
+        #echo "#############################"
+        cd $TESTDIR
+        eval $ENVCMD $RUNCMD $H5DIFF_BIN "$@"
     ) >$actual 2>$actual_err
     EXIT_CODE=$?
+
     # save actual and actual_err in case they are needed later.
     cp $actual $actual_sav
     STDOUT_FILTER $actual
     cp $actual_err $actual_err_sav
     STDERR_FILTER $actual_err
     cat $actual_err >> $actual
+
     # don't add exit code check in pmode, as it causes failure. (exit code
     # is from mpirun not tool)
     # if any problem occurs relate to an exit code, it will be caught in
@@ -259,27 +261,29 @@ TOOLTEST() {
         actual_sorted=actual_sorted
         sort $expect -o $expect_sorted
         sort $actual -o $actual_sorted
+
         # remove "EXIT CODE:" line from expect file. test for exit code
         # is done by serial mode.
         grep -v "EXIT CODE:" $expect_sorted > $expect_sorted.noexit
         mv $expect_sorted.noexit $expect_sorted
-    if $CMP $expect_sorted $actual_sorted; then
-        echo " PASSED"
-    else
-        echo "*FAILED*"
-        nerrors="`expr $nerrors + 1`"
-        if test yes = "$verbose"; then
-        echo "====Expected result ($expect_sorted) differs from actual result ($actual_sorted)"
-        $DIFF $expect_sorted $actual_sorted |sed 's/^/    /'
-        echo "====The actual output ($actual_sav)"
-        sed 's/^/    /' < $actual_sav
-        echo "====The actual stderr ($actual_err_sav)"
-        sed 's/^/    /' < $actual_err_sav
-        echo "====End of actual stderr ($actual_err_sav)"
-        echo ""
+
+        if $CMP $expect_sorted $actual_sorted; then
+            echo " PASSED"
+        else
+            echo "*FAILED*"
+            nerrors="`expr $nerrors + 1`"
+            if test yes = "$verbose"; then
+                echo "====Expected result ($expect_sorted) differs from actual result ($actual_sorted)"
+                $DIFF $expect_sorted $actual_sorted |sed 's/^/    /'
+                echo "====The actual output ($actual_sav)"
+                sed 's/^/    /' < $actual_sav
+                echo "====The actual stderr ($actual_err_sav)"
+                sed 's/^/    /' < $actual_err_sav
+                echo "====End of actual stderr ($actual_err_sav)"
+                echo ""
+            fi
         fi
     fi
-    fi
 
     # Clean up output file
     if test -z "$HDF5_NOCLEANUP"; then
@@ -305,18 +309,20 @@ TOOLTEST_ERR() {
     # Run test.
     TESTING $H5DIFF $@
     (
-    #echo "#############################"
-    #echo "Expected output for '$H5DIFF $@'"
-    #echo "#############################"
-    cd $TESTDIR
-    eval $ENVCMD $RUNCMD $H5DIFF_BIN "$@"
+        #echo "#############################"
+        #echo "Expected output for '$H5DIFF $@'"
+        #echo "#############################"
+        cd $TESTDIR
+        eval $ENVCMD $RUNCMD $H5DIFF_BIN "$@"
     ) >$actual 2>$actual_err
     EXIT_CODE=$?
+
     # save actual and actual_err in case they are needed later.
     cp $actual $actual_sav
     STDOUT_FILTER $actual
     cp $actual_err $actual_err_sav
     STDERR_FILTER $actual_err
+
     # don't add exit code check in pmode, as it causes failure. (exit code
     # is from mpirun not tool)
     # if any problem occurs relate to an exit code, it will be caught in
@@ -347,23 +353,24 @@ TOOLTEST_ERR() {
         sort $expect_err -o $expect_sorted
         sort $actual_err -o $actual_sorted
         mv $expect_sorted.noexit $expect_sorted
-    if $CMP $expect_sorted $actual_sorted; then
-        echo " PASSED"
-    else
-        echo "*FAILED*"
-        nerrors="`expr $nerrors + 1`"
-        if test yes = "$verbose"; then
-        echo "====Expected result ($expect_sorted) differs from actual result ($actual_sorted)"
-        $DIFF $expect_sorted $actual_sorted |sed 's/^/    /'
-        echo "====The actual output ($actual_sav)"
-        sed 's/^/    /' < $actual_sav
-        echo "====The actual stderr ($actual_err_sav)"
-        sed 's/^/    /' < $actual_err_sav
-        echo "====End of actual stderr ($actual_err_sav)"
-        echo ""
+
+        if $CMP $expect_sorted $actual_sorted; then
+            echo " PASSED"
+        else
+            echo "*FAILED*"
+            nerrors="`expr $nerrors + 1`"
+            if test yes = "$verbose"; then
+                echo "====Expected result ($expect_sorted) differs from actual result ($actual_sorted)"
+                $DIFF $expect_sorted $actual_sorted |sed 's/^/    /'
+                echo "====The actual output ($actual_sav)"
+                sed 's/^/    /' < $actual_sav
+                echo "====The actual stderr ($actual_err_sav)"
+                sed 's/^/    /' < $actual_err_sav
+                echo "====End of actual stderr ($actual_err_sav)"
+                echo ""
+            fi
         fi
     fi
-    fi
 
     # Clean up output file
     if test -z "$HDF5_NOCLEANUP"; then
diff --git a/tools/h5diff/testfiles/h5diff_10.txt b/tools/h5diff/testfiles/h5diff_10.txt
index 0618705..5804ac3 100644
--- a/tools/h5diff/testfiles/h5diff_10.txt
+++ b/tools/h5diff/testfiles/h5diff_10.txt
@@ -131,6 +131,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_600.txt b/tools/h5diff/testfiles/h5diff_600.txt
index 98c80be..fa7447b 100644
--- a/tools/h5diff/testfiles/h5diff_600.txt
+++ b/tools/h5diff/testfiles/h5diff_600.txt
@@ -131,6 +131,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_603.txt b/tools/h5diff/testfiles/h5diff_603.txt
index a5bb805..9e1dc89 100644
--- a/tools/h5diff/testfiles/h5diff_603.txt
+++ b/tools/h5diff/testfiles/h5diff_603.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_606.txt b/tools/h5diff/testfiles/h5diff_606.txt
index 4782e17..146b944 100644
--- a/tools/h5diff/testfiles/h5diff_606.txt
+++ b/tools/h5diff/testfiles/h5diff_606.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_612.txt b/tools/h5diff/testfiles/h5diff_612.txt
index ee40713..511e693 100644
--- a/tools/h5diff/testfiles/h5diff_612.txt
+++ b/tools/h5diff/testfiles/h5diff_612.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_615.txt b/tools/h5diff/testfiles/h5diff_615.txt
index 5504812..c4b41f9 100644
--- a/tools/h5diff/testfiles/h5diff_615.txt
+++ b/tools/h5diff/testfiles/h5diff_615.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_621.txt b/tools/h5diff/testfiles/h5diff_621.txt
index e4dba56..9dd312d 100644
--- a/tools/h5diff/testfiles/h5diff_621.txt
+++ b/tools/h5diff/testfiles/h5diff_621.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_622.txt b/tools/h5diff/testfiles/h5diff_622.txt
index 0e7ffa3..0f7c4af 100644
--- a/tools/h5diff/testfiles/h5diff_622.txt
+++ b/tools/h5diff/testfiles/h5diff_622.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_623.txt b/tools/h5diff/testfiles/h5diff_623.txt
index bb70458..3e1b5f3 100644
--- a/tools/h5diff/testfiles/h5diff_623.txt
+++ b/tools/h5diff/testfiles/h5diff_623.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_624.txt b/tools/h5diff/testfiles/h5diff_624.txt
index cb30023..0645961 100644
--- a/tools/h5diff/testfiles/h5diff_624.txt
+++ b/tools/h5diff/testfiles/h5diff_624.txt
@@ -132,6 +132,18 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
 
+ Subsetting options:
+  Subsetting is available by using the fcompact form of subsetting, as follows:
+    obj1 /foo/mydataset[START;STRIDE;COUNT;BLOCK]
+  It is not required to use all parameters, but until the last parameter value used,
+  all of the semicolons (;) are required, even when a parameter value is not specified. Example:
+    obj1 /foo/mydataset[START;;COUNT;BLOCK]
+    obj1 /foo/mydataset[START]
+  The STRIDE, COUNT, and BLOCK parameters are optional and will default to 1 in
+  each dimension. START is optional and will default to 0 in each dimension.
+  Each of START, STRIDE, COUNT, and BLOCK must be a comma-separated list of integers with
+  one integer for each dimension of the dataset.
+
  Exit code:
   0 if no differences, 1 if differences found, 2 if error
 
diff --git a/tools/h5diff/testfiles/h5diff_830.txt b/tools/h5diff/testfiles/h5diff_830.txt
new file mode 100644
index 0000000..8f00d8b
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_830.txt
@@ -0,0 +1,30 @@
+dataset: </g1/array3D> and </g1/array3D>
+size:           [4x3x2]           [4x3x2]
+position        array3D         array3D         difference          
+------------------------------------------------------------
+[ 0 0 0 ]          1               0               1              
+[ 0 0 0 ]          2               0               2              
+[ 0 0 0 ]          3               0               3              
+[ 0 0 1 ]          4               0               4              
+[ 0 0 1 ]          5               0               5              
+[ 0 0 1 ]          6               0               6              
+[ 0 2 0 ]          13              0               13             
+[ 0 2 0 ]          14              0               14             
+[ 0 2 0 ]          15              0               15             
+[ 0 2 1 ]          16              0               16             
+[ 0 2 1 ]          17              0               17             
+[ 0 2 1 ]          18              0               18             
+[ 2 0 0 ]          37              0               37             
+[ 2 0 0 ]          38              0               38             
+[ 2 0 0 ]          39              0               39             
+[ 2 0 1 ]          40              0               40             
+[ 2 0 1 ]          41              0               41             
+[ 2 0 1 ]          42              0               42             
+[ 2 2 0 ]          49              0               49             
+[ 2 2 0 ]          50              0               50             
+[ 2 2 0 ]          51              0               51             
+[ 2 2 1 ]          52              0               52             
+[ 2 2 1 ]          53              0               53             
+[ 2 2 1 ]          54              0               54             
+24 differences found
+EXIT CODE: 1
diff --git a/tools/h5diff/testh5diff.sh.in b/tools/h5diff/testh5diff.sh.in
index 179e7dc..688af68 100644
--- a/tools/h5diff/testh5diff.sh.in
+++ b/tools/h5diff/testh5diff.sh.in
@@ -311,6 +311,7 @@ $SRC_H5DIFF_TESTFILES/h5diff_708.txt
 $SRC_H5DIFF_TESTFILES/h5diff_709.txt
 $SRC_H5DIFF_TESTFILES/h5diff_710.txt
 $SRC_H5DIFF_TESTFILES/h5diff_80.txt
+$SRC_H5DIFF_TESTFILES/h5diff_830.txt
 $SRC_H5DIFF_TESTFILES/h5diff_90.txt
 $SRC_H5DIFF_TESTFILES/h5diff_8625.txt
 $SRC_H5DIFF_TESTFILES/h5diff_8639.txt
@@ -1130,6 +1131,10 @@ TOOLTEST h5diff_644.txt -v --use-system-epsilon -d 5 h5diff_basic1.h5 h5diff_bas
 TOOLTEST h5diff_645.txt -v -p 0.05 --use-system-epsilon h5diff_basic1.h5 h5diff_basic2.h5 /g1/dset3 /g1/dset4
 TOOLTEST h5diff_646.txt -v --use-system-epsilon -p 0.05 h5diff_basic1.h5 h5diff_basic2.h5 /g1/dset3 /g1/dset4
 
+# ##############################################################################
+# # dataset subsets
+# ##############################################################################
+#TRILABS_227 TOOLTEST h5diff_830.txt --enable-error-stack -v h5diff_dset1.h5 h5diff_dset2.h5 /g1/array3D[0,0,0;2,2,1;2,2,2;] /g1/array3D[0,0,0;2,2,1;2,2,2;]
 
 # ##############################################################################
 # # END