[svn-r19781] Fix for bug #1930:

1) Move the test for H5D_EXT_PREFIX in links.c to a separate file: links_env.c
2) links_env.c will be used by testlinks_env.sh to test for the environmental
   variable H5D_EXT_PREFIX in searching for the external linked file.

6 files changed, 261 insertions, 117 deletions

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 0d60993..b39de38 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -287,6 +287,7 @@ SET (H5_TESTS
     err_compat
     tcheck_version
     testmeta
+    links_env
 )
 
 FOREACH (test ${H5_TESTS})
@@ -398,6 +399,7 @@ 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 9464d46..6993a35 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 cache_tagging \
 # '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
@@ -134,6 +134,6 @@ 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.sh
 
 include $(top_srcdir)/config/conclude.am
diff --git a/test/Makefile.in b/test/Makefile.in
index 8748032..b083741 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 = $(noinst_LTLIBRARIES)
 libh5test_la_LIBADD =
@@ -298,6 +299,10 @@ links_SOURCES = links.c
 links_OBJECTS = links.$(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)
@@ -399,8 +404,8 @@ SOURCES = $(libh5test_la_SOURCES) accum.c app_ref.c big.c bittests.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_specmetaread.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 \
@@ -414,8 +419,8 @@ DIST_SOURCES = $(libh5test_la_SOURCES) accum.c app_ref.c big.c \
 	gen_new_mtime.c gen_new_super.c gen_noencoder.c \
 	gen_nullspace.c gen_sizes_lheap.c gen_specmetaread.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 \
 	$(ttsafe_SOURCES) unlink.c vfd.c
 ETAGS = etags
@@ -723,9 +728,9 @@ CHECK_CLEANFILES = *.chkexe *.chklog *.clog accum.h5 cmpd_dset.h5 \
 INCLUDES = -I$(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.
@@ -778,7 +783,7 @@ 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.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.,
@@ -837,6 +842,8 @@ 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 $(noinst_LTLIBRARIES)
@@ -1016,6 +1023,9 @@ lheap$(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) $(LIBS)
@@ -1126,6 +1136,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(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/links.c b/test/links.c
index 3596f1f..e4aead6 100644
--- a/test/links.c
+++ b/test/links.c
@@ -2707,110 +2707,9 @@ 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"
@@ -14015,7 +13914,6 @@ 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/testlinks_env.sh.in b/test/testlinks_env.sh.in
new file mode 100644
index 0000000..9ea85b1
--- /dev/null
+++ b/test/testlinks_env.sh.in
@@ -0,0 +1,41 @@
+#! /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 "$srcdir"; then
+   srcdir=.
+fi
+
+##############################################################################
+##############################################################################
+###			  T H E   T E S T S                                ###
+##############################################################################
+##############################################################################
+
+# test for external links with HDF5_EXT_PREFIX
+echo "Testing external link with HDF5_EXT_PREFIX"
+env "HDF5_EXT_PREFIX=.:tmp" links_env
+exitcode=$?
+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