[svn-r19824] 1. Made fixes as in rev #19813 in trunk:

   a) Add comments to test_4() in test/external.c about the name "/ link".
   b) Fix one memory leak in src/H5Lexternal.c: free memory pointed to by tmp_env_prefix for HDF5_EXT_PREFIX case.
3. Made changes for bug #1930 as in rev #19783, #19781 in trunk.
4. Made corresponding CMake changes as in rev #19782 in trunk.

12 files changed, 307 insertions, 122 deletions

diff --git a/MANIFEST b/MANIFEST
index 46dbb21..a390cd4 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -808,6 +808,7 @@
 ./test/external.c
 ./test/error_test.c
 ./test/err_compat.c
+./test/links_env.c
 ./test/family_v16_00000.h5
 ./test/family_v16_00001.h5
 ./test/family_v16_00002.h5
@@ -876,6 +877,7 @@
 ./test/tcoords.c
 ./test/testcheck_version.sh.in
 ./test/testerror.sh.in
+./test/testlinks_env.sh.in
 ./test/testframe.c
 ./test/testhdf5.c
 ./test/testhdf5.h
@@ -922,6 +924,7 @@
 ./test/testfiles/err_compat_2
 ./test/testfiles/error_test_1
 ./test/testfiles/error_test_2
+./test/testfiles/links_env.out
 
 ./testpar/COPYING
 ./testpar/Makefile.am
diff --git a/configure b/configure
index b665f1d..c3739b5 100755
--- a/configure
+++ b/configure
@@ -28513,7 +28513,7 @@ if test -n "$TESTPARALLEL"; then
   fi
 fi
 
-ac_config_files="$ac_config_files src/libhdf5.settings Makefile src/Makefile test/Makefile test/testcheck_version.sh test/testerror.sh test/H5srcdir_str.h test/testlibinfo.sh testpar/Makefile testpar/testph5.sh perform/Makefile tools/Makefile tools/h5dump/Makefile tools/h5dump/testh5dump.sh tools/h5dump/testh5dumpxml.sh tools/h5ls/testh5ls.sh tools/h5import/Makefile tools/h5diff/Makefile tools/h5jam/Makefile tools/h5jam/testh5jam.sh tools/h5repack/Makefile tools/h5repack/h5repack.sh tools/h5ls/Makefile tools/h5copy/Makefile tools/lib/Makefile tools/misc/Makefile tools/misc/h5cc tools/misc/testh5repart.sh tools/h5stat/testh5stat.sh tools/h5stat/Makefile examples/Makefile examples/run-c-ex.sh examples/testh5cc.sh c++/Makefile c++/src/Makefile c++/src/h5c++ c++/test/Makefile c++/test/H5srcdir_str.h c++/examples/Makefile c++/examples/run-c++-ex.sh c++/examples/testh5c++.sh fortran/Makefile fortran/src/h5fc fortran/src/Makefile fortran/test/Makefile fortran/testpar/Makefile fortran/examples/Makefile fortran/examples/run-fortran-ex.sh fortran/examples/testh5fc.sh hl/Makefile hl/src/Makefile hl/test/Makefile hl/test/H5srcdir_str.h hl/tools/Makefile hl/tools/gif2h5/Makefile hl/examples/Makefile hl/examples/run-hlc-ex.sh hl/c++/Makefile hl/c++/src/Makefile hl/c++/test/Makefile hl/c++/examples/Makefile hl/c++/examples/run-hlc++-ex.sh hl/fortran/Makefile hl/fortran/src/Makefile hl/fortran/test/Makefile hl/fortran/examples/Makefile hl/fortran/examples/run-hlfortran-ex.sh"
+ac_config_files="$ac_config_files src/libhdf5.settings Makefile src/Makefile test/Makefile test/testcheck_version.sh test/testerror.sh test/H5srcdir_str.h test/testlibinfo.sh test/testlinks_env.sh testpar/Makefile testpar/testph5.sh perform/Makefile tools/Makefile tools/h5dump/Makefile tools/h5dump/testh5dump.sh tools/h5dump/testh5dumpxml.sh tools/h5ls/testh5ls.sh tools/h5import/Makefile tools/h5diff/Makefile tools/h5jam/Makefile tools/h5jam/testh5jam.sh tools/h5repack/Makefile tools/h5repack/h5repack.sh tools/h5ls/Makefile tools/h5copy/Makefile tools/lib/Makefile tools/misc/Makefile tools/misc/h5cc tools/misc/testh5repart.sh tools/h5stat/testh5stat.sh tools/h5stat/Makefile examples/Makefile examples/run-c-ex.sh examples/testh5cc.sh c++/Makefile c++/src/Makefile c++/src/h5c++ c++/test/Makefile c++/test/H5srcdir_str.h c++/examples/Makefile c++/examples/run-c++-ex.sh c++/examples/testh5c++.sh fortran/Makefile fortran/src/h5fc fortran/src/Makefile fortran/test/Makefile fortran/testpar/Makefile fortran/examples/Makefile fortran/examples/run-fortran-ex.sh fortran/examples/testh5fc.sh hl/Makefile hl/src/Makefile hl/test/Makefile hl/test/H5srcdir_str.h hl/tools/Makefile hl/tools/gif2h5/Makefile hl/examples/Makefile hl/examples/run-hlc-ex.sh hl/c++/Makefile hl/c++/src/Makefile hl/c++/test/Makefile hl/c++/examples/Makefile hl/c++/examples/run-hlc++-ex.sh hl/fortran/Makefile hl/fortran/src/Makefile hl/fortran/test/Makefile hl/fortran/examples/Makefile hl/fortran/examples/run-hlfortran-ex.sh"
 
 
 cat >confcache <<\_ACEOF
@@ -29747,6 +29747,7 @@ do
     "test/testerror.sh") CONFIG_FILES="$CONFIG_FILES test/testerror.sh" ;;
     "test/H5srcdir_str.h") CONFIG_FILES="$CONFIG_FILES test/H5srcdir_str.h" ;;
     "test/testlibinfo.sh") CONFIG_FILES="$CONFIG_FILES test/testlibinfo.sh" ;;
+    "test/testlinks_env.sh") CONFIG_FILES="$CONFIG_FILES test/testlinks_env.sh" ;;
     "testpar/Makefile") CONFIG_FILES="$CONFIG_FILES testpar/Makefile" ;;
     "testpar/testph5.sh") CONFIG_FILES="$CONFIG_FILES testpar/testph5.sh" ;;
     "perform/Makefile") CONFIG_FILES="$CONFIG_FILES perform/Makefile" ;;
diff --git a/configure.in b/configure.in
index f6342d7..794c664 100644
--- a/configure.in
+++ b/configure.in
@@ -4390,6 +4390,7 @@ AC_CONFIG_FILES([src/libhdf5.settings
                  test/testerror.sh
                  test/H5srcdir_str.h
                  test/testlibinfo.sh
+                 test/testlinks_env.sh
                  testpar/Makefile
                  testpar/testph5.sh
                  perform/Makefile
diff --git a/src/H5Lexternal.c b/src/H5Lexternal.c
index 9cab8cf..4700fee 100644
--- a/src/H5Lexternal.c
+++ b/src/H5Lexternal.c
@@ -188,6 +188,9 @@ done:
  *		Otherwise, the file access property retrieved from H5Pget_elink_fapl()
  *		is used to H5F_open() the target file.
  *
+ *              Vailin Choi; Nov 2010
+ *              Free memory pointed to by tmp_env_prefix for HDF5_EXT_PREFIX case.
+ *
  *-------------------------------------------------------------------------
  */
 static hid_t
@@ -343,9 +346,9 @@ H5L_extern_traverse(const char UNUSED *link_name, hid_t cur_group,
         char *env_prefix;
 
         if(NULL != (env_prefix = HDgetenv("HDF5_EXT_PREFIX"))) {
-            char *tmp_env_prefix;
+            char *tmp_env_prefix, *saved_env;
 
-            if(NULL == (tmp_env_prefix = H5MM_strdup(env_prefix)))
+            if(NULL == (saved_env = tmp_env_prefix = H5MM_strdup(env_prefix)))
                 HGOTO_ERROR(H5E_LINK, H5E_NOSPACE, FAIL, "memory allocation failed")
 
             while((tmp_env_prefix) && (*tmp_env_prefix)) {
@@ -353,8 +356,10 @@ H5L_extern_traverse(const char UNUSED *link_name, hid_t cur_group,
 
                 out_prefix_name = H5L_getenv_prefix_name(&tmp_env_prefix/*in,out*/);
                 if(out_prefix_name && (*out_prefix_name)) {
-                    if(H5L_build_name(out_prefix_name, temp_file_name, &full_name/*out*/) < 0)
+                    if(H5L_build_name(out_prefix_name, temp_file_name, &full_name/*out*/) < 0) {
+			saved_env = (char *)H5MM_xfree(saved_env);
                         HGOTO_ERROR(H5E_LINK, H5E_CANTGET, FAIL, "can't prepend prefix to filename")
+		    }
 
                     ext_file = H5F_open(full_name, intent, H5P_FILE_CREATE_DEFAULT, fapl_id, H5AC_dxpl_id);
                     full_name = (char *)H5MM_xfree(full_name);
@@ -363,6 +368,7 @@ H5L_extern_traverse(const char UNUSED *link_name, hid_t cur_group,
                     H5E_clear_stack(NULL);
                 } /* end if */
             } /* end while */
+	    saved_env = (char *)H5MM_xfree(saved_env);
         } /* end if */
     } /* end if */
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 1bb1b48..158110b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -55,6 +55,7 @@ SET (HDF5_REFERENCE_FILES
     err_compat_2
     error_test_1
     error_test_2
+    links_env.out
 )
 
 FOREACH (ref_file ${HDF5_REFERENCE_FILES})
@@ -283,6 +284,7 @@ SET (H5_TESTS
     #err_compat
     tcheck_version
     testmeta
+    #links_env
 )
 
 FOREACH (test ${H5_TESTS})
@@ -362,6 +364,24 @@ ADD_TEST (NAME error_test COMMAND "${CMAKE_COMMAND}"
     -P "${HDF5_RESOURCES_DIR}/runTest.cmake"
 )
 
+#-- Adding test for links_env
+ADD_EXECUTABLE (links_env ${HDF5_TEST_SOURCE_DIR}/links_env.c)
+H5_NAMING (links_env)
+TARGET_WIN_PROPERTIES (links_env)
+TARGET_LINK_LIBRARIES (links_env ${HDF5_LIB_TARGET} ${HDF5_TEST_LIB_TARGET})
+
+ADD_TEST (NAME links_env COMMAND "${CMAKE_COMMAND}"
+    -D "TEST_PROGRAM=$<TARGET_FILE:links_env>"
+    -D "TEST_ARGS:STRING="
+    -D "TEST_ENV_VAR:STRING=HDF5_EXT_PREFIX"
+    -D "TEST_ENV_VALUE:STRING=.:tmp"
+    -D "TEST_EXPECT=0"
+    -D "TEST_OUTPUT=links_env.txt"
+    -D "TEST_REFERENCE=links_env.out"
+    -D "TEST_FOLDER=${PROJECT_BINARY_DIR}"
+    -P "${HDF5_RESOURCES_DIR}/runTest.cmake"
+)
+
 IF (HDF5_TEST_VFD)
 
   SET (VFD_LIST
@@ -421,6 +441,7 @@ IF (HDF5_TEST_VFD)
       err_compat
       tcheck_version
       testmeta
+      links_env
 )
   
   IF (DIRECT_VFD)
diff --git a/test/Makefile.am b/test/Makefile.am
index b37ad53..4493f4f 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -24,9 +24,9 @@ include $(top_srcdir)/config/commence.am
 INCLUDES=-I$(top_srcdir)/src -I$(top_builddir)/src
 
 # Test script for error_test and err_compat
-TEST_SCRIPT = testerror.sh testlibinfo.sh testcheck_version.sh
+TEST_SCRIPT = testerror.sh testlibinfo.sh testcheck_version.sh testlinks_env.sh
 check_SCRIPTS = $(TEST_SCRIPT)
-SCRIPT_DEPEND = error_test$(EXEEXT) err_compat$(EXEEXT)
+SCRIPT_DEPEND = error_test$(EXEEXT) err_compat$(EXEEXT) links_env$(EXEEXT)
 
 
 # These are our main targets. They should be listed in the order to be
@@ -50,7 +50,7 @@ TEST_PROG=testhdf5 lheap ohdr stab gheap cache cache_api \
 # 'make check' doesn't run them directly, so they are not included in TEST_PROG.
 # Also build testmeta, which is used for timings test.  It builds quickly,
 # and this lets automake keep all its test programs in one place.
-check_PROGRAMS=$(TEST_PROG) error_test err_compat tcheck_version testmeta
+check_PROGRAMS=$(TEST_PROG) error_test err_compat tcheck_version testmeta links_env
 
 
 # These programs generate test files for the tests.  They don't need to be
@@ -133,6 +133,6 @@ testhdf5_SOURCES=testhdf5.c tarray.c tattr.c tchecksum.c tconfig.c tfile.c \
     tvlstr.c tvltypes.c
 
 # Temporary files.
-DISTCLEANFILES=testerror.sh testlibinfo.sh testcheck_version.sh
+DISTCLEANFILES=testerror.sh testlibinfo.sh testcheck_version.sh testlinks_env.sh
 
 include $(top_srcdir)/config/conclude.am
diff --git a/test/Makefile.in b/test/Makefile.in
index 0d996e7..c8ebf75 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -55,10 +55,11 @@ host_triplet = @host@
 DIST_COMMON = $(srcdir)/H5srcdir_str.h.in $(srcdir)/Makefile.am \
 	$(srcdir)/Makefile.in $(srcdir)/testcheck_version.sh.in \
 	$(srcdir)/testerror.sh.in $(srcdir)/testlibinfo.sh.in \
-	$(top_srcdir)/config/commence.am \
+	$(srcdir)/testlinks_env.sh.in $(top_srcdir)/config/commence.am \
 	$(top_srcdir)/config/conclude.am COPYING
 check_PROGRAMS = $(am__EXEEXT_1) error_test$(EXEEXT) \
-	err_compat$(EXEEXT) tcheck_version$(EXEEXT) testmeta$(EXEEXT)
+	err_compat$(EXEEXT) tcheck_version$(EXEEXT) testmeta$(EXEEXT) \
+	links_env$(EXEEXT)
 @BUILD_ALL_CONDITIONAL_TRUE@noinst_PROGRAMS = $(am__EXEEXT_2)
 TESTS = $(check_PROGRAMS) $(check_SCRIPTS)
 subdir = test
@@ -69,7 +70,7 @@ am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 mkinstalldirs = $(SHELL) $(top_srcdir)/bin/mkinstalldirs
 CONFIG_HEADER = $(top_builddir)/src/H5config.h
 CONFIG_CLEAN_FILES = testcheck_version.sh testerror.sh H5srcdir_str.h \
-	testlibinfo.sh
+	testlibinfo.sh testlinks_env.sh
 CONFIG_CLEAN_VPATH_FILES =
 LTLIBRARIES = $(noinst_LTLIBRARIES)
 libh5test_la_LIBADD =
@@ -280,6 +281,10 @@ links_SOURCES = links.c
 links_OBJECTS = links.$(OBJEXT)
 links_LDADD = $(LDADD)
 links_DEPENDENCIES = libh5test.la $(LIBHDF5)
+links_env_SOURCES = links_env.c
+links_env_OBJECTS = links_env.$(OBJEXT)
+links_env_LDADD = $(LDADD)
+links_env_DEPENDENCIES = libh5test.la $(LIBHDF5)
 mf_SOURCES = mf.c
 mf_OBJECTS = mf.$(OBJEXT)
 mf_LDADD = $(LDADD)
@@ -380,8 +385,8 @@ SOURCES = $(libh5test_la_SOURCES) accum.c app_ref.c big.c bittests.c \
 	gen_new_array.c gen_new_fill.c gen_new_group.c gen_new_mtime.c \
 	gen_new_super.c gen_noencoder.c gen_nullspace.c \
 	gen_sizes_lheap.c gen_udlinks.c getname.c gheap.c hyperslab.c \
-	istore.c lheap.c links.c mf.c mount.c mtime.c ntypes.c \
-	objcopy.c ohdr.c pool.c reserved.c set_extent.c \
+	istore.c lheap.c links.c links_env.c mf.c mount.c mtime.c \
+	ntypes.c objcopy.c ohdr.c pool.c reserved.c set_extent.c \
 	space_overflow.c stab.c tcheck_version.c $(testhdf5_SOURCES) \
 	testmeta.c $(ttsafe_SOURCES) unlink.c vfd.c
 DIST_SOURCES = $(libh5test_la_SOURCES) accum.c app_ref.c big.c \
@@ -394,8 +399,8 @@ DIST_SOURCES = $(libh5test_la_SOURCES) accum.c app_ref.c big.c \
 	gen_new_group.c gen_new_mtime.c gen_new_super.c \
 	gen_noencoder.c gen_nullspace.c gen_sizes_lheap.c \
 	gen_udlinks.c getname.c gheap.c hyperslab.c istore.c lheap.c \
-	links.c mf.c mount.c mtime.c ntypes.c objcopy.c ohdr.c pool.c \
-	reserved.c set_extent.c space_overflow.c stab.c \
+	links.c links_env.c mf.c mount.c mtime.c ntypes.c objcopy.c \
+	ohdr.c pool.c reserved.c set_extent.c space_overflow.c stab.c \
 	tcheck_version.c $(testhdf5_SOURCES) testmeta.c \
 	$(ttsafe_SOURCES) unlink.c vfd.c
 ETAGS = etags
@@ -704,9 +709,9 @@ CHECK_CLEANFILES = *.chkexe *.chklog *.clog accum.h5 cmpd_dset.h5 \
 INCLUDES = -I$(top_srcdir)/src -I$(top_builddir)/src
 
 # Test script for error_test and err_compat
-TEST_SCRIPT = testerror.sh testlibinfo.sh testcheck_version.sh
+TEST_SCRIPT = testerror.sh testlibinfo.sh testcheck_version.sh testlinks_env.sh
 check_SCRIPTS = $(TEST_SCRIPT)
-SCRIPT_DEPEND = error_test$(EXEEXT) err_compat$(EXEEXT)
+SCRIPT_DEPEND = error_test$(EXEEXT) err_compat$(EXEEXT) links_env$(EXEEXT)
 
 # These are our main targets. They should be listed in the order to be
 # executed, generally most specific tests to least specific tests.
@@ -758,7 +763,7 @@ testhdf5_SOURCES = testhdf5.c tarray.c tattr.c tchecksum.c tconfig.c tfile.c \
 
 
 # Temporary files.
-DISTCLEANFILES = testerror.sh testlibinfo.sh testcheck_version.sh
+DISTCLEANFILES = testerror.sh testlibinfo.sh testcheck_version.sh testlinks_env.sh
 
 # Automake needs to be taught how to build lib, progs, and tests targets.
 # These will be filled in automatically for the most part (e.g.,
@@ -817,6 +822,8 @@ H5srcdir_str.h: $(top_builddir)/config.status $(srcdir)/H5srcdir_str.h.in
 	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
 testlibinfo.sh: $(top_builddir)/config.status $(srcdir)/testlibinfo.sh.in
 	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+testlinks_env.sh: $(top_builddir)/config.status $(srcdir)/testlinks_env.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
 
 clean-noinstLTLIBRARIES:
 	-test -z "$(noinst_LTLIBRARIES)" || rm -f $(noinst_LTLIBRARIES)
@@ -984,6 +991,9 @@ lheap$(EXEEXT): $(lheap_OBJECTS) $(lheap_DEPENDENCIES)
 links$(EXEEXT): $(links_OBJECTS) $(links_DEPENDENCIES) 
 	@rm -f links$(EXEEXT)
 	$(LINK) $(links_OBJECTS) $(links_LDADD) $(LIBS)
+links_env$(EXEEXT): $(links_env_OBJECTS) $(links_env_DEPENDENCIES) 
+	@rm -f links_env$(EXEEXT)
+	$(LINK) $(links_env_OBJECTS) $(links_env_LDADD) $(LIBS)
 mf$(EXEEXT): $(mf_OBJECTS) $(mf_DEPENDENCIES) 
 	@rm -f mf$(EXEEXT)
 	$(LINK) $(mf_OBJECTS) $(mf_LDADD) $(LIBS)
@@ -1090,6 +1100,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/istore.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lheap.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/links.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/links_env.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/mf.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/mount.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/mtime.Po@am__quote@
diff --git a/test/external.c b/test/external.c
index 7c859d4..484236a 100644
--- a/test/external.c
+++ b/test/external.c
@@ -888,7 +888,7 @@ test_4 (hid_t fapl)
     if((fid = H5Fopen(filename, H5F_ACC_RDONLY, fapl)) < 0)
         goto error;
 
-    /* Open the external link */
+    /* Open the external link which is "/ link" as created previously via H5Lcreate_external() */
     if((xid = H5Gopen2(fid, "/ link", H5P_DEFAULT)) < 0)
         goto error;
 
diff --git a/test/links.c b/test/links.c
index 650f9e8..a1718ed 100644
--- a/test/links.c
+++ b/test/links.c
@@ -2724,110 +2724,9 @@ external_link_dangling(hid_t fapl, hbool_t new_format)
     return -1;
 } /* end external_link_dangling() */
 
-
-
-/*-------------------------------------------------------------------------
- * Function:    external_link_env: test 1
- *
- * Purpose:
- *		1. target link: "extlinks1"
- *		2. main file: "extlinks0"
- *		3. target file: "tmp/extlinks1"
- * 		4. The environment variable "HDF5_EXT_PREFIX" should be set to ".:tmp"
- *		Should be able to access the target file in tmp directory through searching
- *			the pathnames set in HDF5_EXT_PREFIX.
- *		This test will be skipped if HDF5_EXT_PREFIX is not set as expected.
- *
- *
- * Return:      Success:        0
- *              Failure:        -1
- *
- * Programmer:  Vailin Choi
- *              Feb. 20, 2008
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-static int
-external_link_env(hid_t fapl, hbool_t new_format)
-{
-    hid_t	fid = (-1);     		/* File ID */
-    hid_t	gid = (-1);	                /* Group IDs */
-    const char  *envval = NULL;
-
-    char	filename1[NAME_BUF_SIZE],
-    		filename2[NAME_BUF_SIZE],
-    		filename3[NAME_BUF_SIZE];
-
-    if(new_format)
-        TESTING("external links via environment variable (w/new group format)")
-    else
-        TESTING("external links via environment variable")
-
-    if ((envval = HDgetenv("HDF5_EXT_PREFIX")) == NULL)
-        envval = "nomatch";
-    if (HDstrcmp(envval, ".:tmp")) {
-	SKIPPED();
-	return(0);
-    }
-
-    /* set up name for main file:"extlinks0" */
-    h5_fixname(FILENAME[12], fapl, filename1, sizeof filename1);
-    /* set up name for external linked target file: "extlinks1" */
-    h5_fixname(FILENAME[14], fapl, filename2, sizeof filename2);
-
-    if(HDmkdir(TMPDIR, (mode_t)0755) < 0 && errno != EEXIST)
-	TEST_ERROR
-
-    /* set up name for target file: "tmp/extlinks1" */
-    h5_fixname(FILENAME[15], fapl, filename3, sizeof filename3);
-
-    /* Create the target file */
-    if((fid=H5Fcreate(filename3, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0) TEST_ERROR
-    if((gid=H5Gcreate2(fid, "A", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
-
-    /* closing for target file */
-    if(H5Gclose(gid) < 0) TEST_ERROR
-    if(H5Fclose(fid) < 0) TEST_ERROR
-
-
-    /* Create the main file */
-    if((fid=H5Fcreate(filename1, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0) TEST_ERROR
-
-    /* Create external link to target file */
-    if(H5Lcreate_external(filename2, "/A", fid, "ext_link", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
-
-    /* Open object through external link */
-    H5E_BEGIN_TRY {
-        gid = H5Gopen2(fid, "ext_link", H5P_DEFAULT);
-    } H5E_END_TRY;
-
-    /* should be able to find the target file from pathnames set via environment variable */
-    if (gid < 0) {
-	H5_FAILED();
-	puts("    Should have found the file in tmp directory.");
-	goto error;
-    }
-
-    /* closing for main file */
-    if(H5Gclose(gid) < 0) TEST_ERROR
-    if(H5Fclose(fid) < 0) TEST_ERROR
-
-    PASSED();
-    return 0;
-
- error:
-    H5E_BEGIN_TRY {
-	H5Gclose (gid);
-	H5Fclose (fid);
-    } H5E_END_TRY;
-    return -1;
-} /* end external_link_env() */
-
 
 /*-------------------------------------------------------------------------
- * Function:    external_link_prefix: test 2
+ * Function:    external_link_prefix
  *
  * Purpose:     1. target link: "extlinks2"
  *		2. main file: "extlinks0"
@@ -14058,7 +13957,6 @@ main(void)
         nerrors += external_link_strong(my_fapl, new_format) < 0 ? 1 : 0;
 
         /* tests for external link */
-        nerrors += external_link_env(my_fapl, new_format) < 0 ? 1 : 0;
         nerrors += external_link_prefix(my_fapl, new_format) < 0 ? 1 : 0;
         nerrors += external_link_abs_mainpath(my_fapl, new_format) < 0 ? 1 : 0;
         nerrors += external_link_rel_mainpath(my_fapl, new_format) < 0 ? 1 : 0;
diff --git a/test/links_env.c b/test/links_env.c
new file mode 100644
index 0000000..c792386
--- /dev/null
+++ b/test/links_env.c
@@ -0,0 +1,192 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:	Tests hard, soft (symbolic) & external links.
+ */
+
+#define H5G_PACKAGE
+#define H5G_TESTING
+
+#include "h5test.h"
+#include "H5srcdir.h"
+#include "H5Gpkg.h"		/* Groups 				*/
+#include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5Lprivate.h"         /* Links                                */
+
+#ifdef H5_VMS
+#define TMPDIR          "[.tmp]"
+#else /* H5_VMS */
+#define TMPDIR          "tmp/"
+#endif /* H5_VMS */
+#define NAME_BUF_SIZE   1024
+
+const char *FILENAME[] = {
+    "extlinks_env0",	/* 0: main file */
+    "extlinks_env1",	/* 1: target file */
+    TMPDIR "extlinks_env1", /* 2 */
+    NULL
+};
+
+static int external_link_env(hid_t fapl, hbool_t new_format);
+
+
+/*-------------------------------------------------------------------------
+ * Function:    external_link_env (moved from links.c)
+ *
+ * Purpose: 	Verify that the target file is found successfully in "tmp" directory
+ *		via searching the pathnames set in the environment variable HDF5_EXT_PREFIX.
+ *		1. Target link: "extlinks_env1"
+ *		2. Main file: "extlinks_env0"
+ *		3. Target file is created in: "tmp/extlinks_env1"
+ * 		4. The environment variable "HDF5_EXT_PREFIX" is set to ".:tmp"
+ *
+ * Return:      Success:        0
+ *              Failure:        -1
+ *
+ * Programmer:  Vailin Choi
+ *              Feb. 20, 2008
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+external_link_env(hid_t fapl, hbool_t new_format)
+{
+    hid_t fid = (-1);     	/* File ID */
+    hid_t gid = (-1);	        /* Group IDs */
+    const char *envval = NULL;	/* Pointer to environment variable */
+    char	filename1[NAME_BUF_SIZE],
+    		filename2[NAME_BUF_SIZE],
+    		filename3[NAME_BUF_SIZE];	/* Holders for filename */
+
+    if(new_format)
+        TESTING("external links via environment variable (w/new group format)")
+    else
+        TESTING("external links via environment variable")
+
+    if ((envval = HDgetenv("HDF5_EXT_PREFIX")) == NULL)
+        envval = "nomatch";
+    if (HDstrcmp(envval, ".:tmp")) TEST_ERROR
+
+    /* Set up name for main file:"extlinks_env0" */
+    h5_fixname(FILENAME[0], fapl, filename1, sizeof filename1);
+
+    /* Set up name for external linked target file: "extlinks_env1" */
+    h5_fixname(FILENAME[1], fapl, filename2, sizeof filename2);
+
+    /* Create "tmp" directory */
+    if(HDmkdir(TMPDIR, (mode_t)0755) < 0 && errno != EEXIST)
+	TEST_ERROR
+
+    /* Set up name (location) for the target file: "tmp/extlinks1" */
+    h5_fixname(FILENAME[2], fapl, filename3, sizeof filename3);
+
+    /* Create the target file in "tmp" directory */
+    if((fid=H5Fcreate(filename3, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0) TEST_ERROR
+    if((gid=H5Gcreate2(fid, "A", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Closing for target file */
+    if(H5Gclose(gid) < 0) TEST_ERROR
+    if(H5Fclose(fid) < 0) TEST_ERROR
+
+
+    /* Create the main file */
+    if((fid=H5Fcreate(filename1, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0) TEST_ERROR
+
+    /* Create external link to target file */
+    if(H5Lcreate_external(filename2, "/A", fid, "ext_link", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+
+    /* Open object through external link */
+    H5E_BEGIN_TRY {
+        gid = H5Gopen2(fid, "ext_link", H5P_DEFAULT);
+    } H5E_END_TRY;
+
+    /* Should be able to find the target file from pathnames set via HDF5_EXT_PREFIX */
+    if (gid < 0) {
+	H5_FAILED();
+	puts("    Should have found the file in tmp directory.");
+	goto error;
+    }
+
+    /* closing for main file */
+    if(H5Gclose(gid) < 0) TEST_ERROR
+    if(H5Fclose(fid) < 0) TEST_ERROR
+
+    PASSED();
+    return 0;
+
+ error:
+    H5E_BEGIN_TRY {
+	H5Gclose (gid);
+	H5Fclose (fid);
+    } H5E_END_TRY;
+    return -1;
+} /* end external_link_env() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	main
+ *
+ * Purpose:	Test external link with environment variable HDF5_EXT_PREFIX
+ *
+ * Return:	Success:	exit(0)
+ *		Failure:	exit(non-zero)
+ *
+ * Programmer:	Vailin Choi; Nov 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+main(void)
+{
+    hid_t fapl; 	/* File access property lists */
+    int	nerrors = 0;	/* Error from tests */
+    const char  *env_h5_drvr;      /* File Driver value from environment */
+
+    env_h5_drvr = HDgetenv("HDF5_DRIVER");
+    if(env_h5_drvr == NULL)
+        env_h5_drvr = "nomatch";
+
+    h5_reset();
+    fapl = h5_fileaccess();
+
+    nerrors += external_link_env(fapl, FALSE) < 0 ? 1 : 0;
+
+    /* Set the "use the latest version of the format" bounds for creating objects in the file */
+    if(H5Pset_libver_bounds(fapl, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0) TEST_ERROR
+
+    nerrors += external_link_env(fapl, TRUE) < 0 ? 1 : 0;
+
+    h5_cleanup(FILENAME, fapl);
+
+    /* Results */
+    if(nerrors) {
+        printf("***** %d External Link (HDF5_EXT_PREFIX) test%s FAILED! *****\n",
+                nerrors, 1 == nerrors ? "" : "s");
+        exit(1);
+    }
+    printf("All external Link (HDF5_EXT_PREFIX) tests passed.\n");
+
+    /* clean up tmp directory created by external link tests */
+    HDrmdir(TMPDIR);
+
+    return 0;
+
+error:
+    puts("*** TESTS FAILED ***");
+    return 1;
+}
diff --git a/test/testfiles/links_env.out b/test/testfiles/links_env.out
new file mode 100644
index 0000000..3ca9b99
--- /dev/null
+++ b/test/testfiles/links_env.out
@@ -0,0 +1,6 @@
+#############################
+Expected output for links_env
+#############################
+Testing external links via environment variable                        PASSED
+Testing external links via environment variable (w/new group format)   PASSED
+All external Link (HDF5_EXT_PREFIX) tests passed.
diff --git a/test/testlinks_env.sh.in b/test/testlinks_env.sh.in
new file mode 100644
index 0000000..e71dfc8
--- /dev/null
+++ b/test/testlinks_env.sh.in
@@ -0,0 +1,46 @@
+#! /bin/sh
+#
+# Copyright by The HDF Group.
+# Copyright by the Board of Trustees of the University of Illinois.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the files COPYING and Copyright.html.  COPYING can be found at the root
+# of the source code distribution tree; Copyright.html can be found at the
+# root level of an installed copy of the electronic HDF5 document set and
+# is linked from the top-level documents page.  It can also be found at
+# http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have
+# access to either file, you may request a copy from help@hdfgroup.org.
+#
+# Test for external link with environment variable: HDF5_EXT_PREFIX
+
+nerrors=0
+
+# The build (current) directory might be different than the source directory.
+if test -z "$srcdir"; then
+   srcdir=.
+fi
+
+##############################################################################
+##############################################################################
+###			  T H E   T E S T S                                ###
+##############################################################################
+##############################################################################
+
+# test for external links with HDF5_EXT_PREFIX
+echo "Testing external link with HDF5_EXT_PREFIX"
+TEST_NAME=links_env 		# The test name
+TEST_BIN=`pwd`/$TEST_NAME 	# The path of the test binary
+ENVCMD="env HDF5_EXT_PREFIX=.:tmp" 	# The environment variable & value
+#
+# Run the test
+$ENVCMD $TEST_BIN
+exitcode=$?
+if [ $exitcode -eq 0 ]; then
+        echo "Test for HDF5_EXT_PREFIX PASSED"
+    else
+ 	nerrors="`expr $nerrors + 1`"
+	echo "***Error encountered for HDF5_EXT_PREFIX test***"
+fi
+exit $nerrors