HDFFV-10246 Fix vl string compare

6 files changed, 53 insertions, 6 deletions

diff --git a/MANIFEST b/MANIFEST
index 3c4b142..55f08a9 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -2021,6 +2021,7 @@
 ./tools/h5diff/testfiles/h5diff_udfail.txt
 ./tools/h5diff/testfiles/diff_strings1.h5
 ./tools/h5diff/testfiles/diff_strings2.h5
+./tools/h5diff/testfiles/h5diff_vlstr.txt
 
 #test files for h5repack
 ./tools/h5repack/testfiles/README
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 792e5b2..cd9a1f5 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -92,7 +92,7 @@ New Features
 
 Support for New Platforms, Languages, and Compilers
 ===================================================
-    
+
 
 
 Bug Fixes since HDF5-1.8.19
@@ -120,7 +120,14 @@ Bug Fixes since HDF5-1.8.19
 
     Tools
     -----
-    - None
+    - h5diff
+
+      h5diff segfaulted on compare of a  NULL variable length string.
+
+      Improved h5diff compare of strings by adding a check for
+      NULL strings and setting the lengths to zero.
+
+      (ADB - 2017/07/25, HDFFV-10246)
 
 
     Fortran API
diff --git a/tools/h5diff/CMakeTests.cmake b/tools/h5diff/CMakeTests.cmake
index 7f6f8c3..e97b78c 100644
--- a/tools/h5diff/CMakeTests.cmake
+++ b/tools/h5diff/CMakeTests.cmake
@@ -66,6 +66,8 @@
       ${HDF5_TOOLS_H5DIFF_SOURCE_DIR}/testfiles/tudfilter2.h5
       ${HDF5_TOOLS_H5DIFF_SOURCE_DIR}/testfiles/diff_strings1.h5
       ${HDF5_TOOLS_H5DIFF_SOURCE_DIR}/testfiles/diff_strings2.h5
+      # tools/testfiles
+      ${HDF5_TOOLS_DIR}/testfiles/tvlstr.h5
   )
 
   set (LIST_OTHER_TEST_FILES
@@ -276,6 +278,8 @@
       HDFTEST_COPY_FILE("${h5_tstfiles}" "${PROJECT_BINARY_DIR}/PAR/testfiles/${fname}" "h5diff_files")
     endif ()
   endforeach ()
+  # copy second version of tvlstr.h5
+  HDFTEST_COPY_FILE("${HDF5_TOOLS_DIR}/testfiles/tvlstr.h5" "${PROJECT_BINARY_DIR}/testfiles/tvlstr2.h5" "h5diff_files")
 
 
   #
@@ -839,6 +843,8 @@
           h5diff_801.out.err
           h5diff_90.out
           h5diff_90.out.err
+          h5diff_vlstr.out
+          h5diff_vlstr.out.err
     )
     set_tests_properties (H5DIFF-clearall-objects PROPERTIES WORKING_DIRECTORY "${PROJECT_BINARY_DIR}/testfiles")
     if (NOT "${last_test}" STREQUAL "")
@@ -1403,6 +1409,7 @@ ADD_H5_TEST (h5diff_487 1 -v --exclude-path "/group1/dset" h5diff_exclude3-1.h5
 # # diff various multiple vlen and fixed strings in a compound type dataset
 # ##############################################################################
 ADD_H5_TEST (h5diff_530 0 -v  ${COMP_VL_STRS_FILE} ${COMP_VL_STRS_FILE} /group /group_copy)
+ADD_H5_TEST (h5diff_vlstr 0 -v tvlstr.h5 tvlstr2.h5)
 
 # ##############################################################################
 # # Test container types (array,vlen) with multiple nested compound types
diff --git a/tools/h5diff/testfiles/h5diff_vlstr.txt b/tools/h5diff/testfiles/h5diff_vlstr.txt
new file mode 100644
index 0000000..67141f1
--- /dev/null
+++ b/tools/h5diff/testfiles/h5diff_vlstr.txt
@@ -0,0 +1,16 @@
+
+file1     file2
+---------------------------------------
+    x      x    /              
+    x      x    /Dataset1      
+    x      x    /vl_string_type
+
+group  : </> and </>
+0 differences found
+attribute: <test_scalar of </>> and <test_scalar of </>>
+0 differences found
+dataset: </Dataset1> and </Dataset1>
+0 differences found
+datatype: </vl_string_type> and </vl_string_type>
+0 differences found
+EXIT CODE: 0
diff --git a/tools/h5diff/testh5diff.sh.in b/tools/h5diff/testh5diff.sh.in
index 45a7a45..c21cbd7 100644
--- a/tools/h5diff/testh5diff.sh.in
+++ b/tools/h5diff/testh5diff.sh.in
@@ -120,6 +120,7 @@ $SRC_H5DIFF_TESTFILES/non_comparables1.h5
 $SRC_H5DIFF_TESTFILES/non_comparables2.h5
 $SRC_H5DIFF_TESTFILES/diff_strings1.h5
 $SRC_H5DIFF_TESTFILES/diff_strings2.h5
+$SRC_TOOLS_TESTFILES/tvlstr.h5
 "
 
 LIST_OTHER_TEST_FILES="
@@ -522,6 +523,8 @@ SKIP() {
 ##############################################################################
 # prepare for test
 COPY_TESTFILES_TO_TESTDIR
+# second copy of tvlstr.h5
+$CP -f $SRC_TOOLS_TESTFILES/tvlstr.h5 $TESTDIR/tvlstr2.h5
 
 # ############################################################################
 # # Common usage
@@ -1097,6 +1100,7 @@ TOOLTEST h5diff_487.txt -v --exclude-path "/group1/dset" h5diff_exclude3-1.h5 h5
 # # diff various multiple vlen and fixed strings in a compound type dataset
 # ##############################################################################
 TOOLTEST h5diff_530.txt -v  h5diff_comp_vl_strs.h5 h5diff_comp_vl_strs.h5 /group /group_copy
+TOOLTEST h5diff_vlstr.txt -v  tvlstr.h5 tvlstr2.h5
 
 # ##############################################################################
 # # Test container types (array,vlen) with multiple nested compound types
diff --git a/tools/lib/h5diff_array.c b/tools/lib/h5diff_array.c
index 1b17382..6480cf6 100644
--- a/tools/lib/h5diff_array.c
+++ b/tools/lib/h5diff_array.c
@@ -674,21 +674,33 @@ static hsize_t diff_datum(void       *_mem1,
                 h5difftrace("diff_datum H5T_STRING variable\n");
                 /* Get pointer to first string */
                 s1 = *(char**) mem1;
-                size1 = HDstrlen(s1);
+                if(s1)
+                    size1 = HDstrlen(s1);
+                else
+                    size1 = 0;
                 /* Get pointer to second string */
                 s2 = *(char**) mem2;
-                size2 = HDstrlen(s2);
+                if(s2)
+                    size2 = HDstrlen(s2);
+                else
+                    size2 = 0;
             }
             else if (H5T_STR_NULLTERM == pad) {
                 h5difftrace("diff_datum H5T_STRING null term\n");
                 /* Get pointer to first string */
                 s1 = (char*) mem1;
-                size1 = HDstrlen(s1);
+                if(s1)
+                    size1 = HDstrlen(s1);
+                else
+                    size1 = 0;
                 if (size1 > size_mtype)
                     size1 = size_mtype;
                 /* Get pointer to second string */
                 s2 = (char*) mem2;
-                size2 = HDstrlen(s2);
+                if(s2)
+                    size2 = HDstrlen(s2);
+                else
+                    size2 = 0;
                 if (size2 > size_mtype)
                     size2 = size_mtype;
             }