diff --git a/releng/test_hardlinks b/releng/test_hardlinks
index e314b208..a009e8b6 100755
--- a/releng/test_hardlinks
+++ b/releng/test_hardlinks
@@ -9,13 +9,44 @@ export prog=$(basename "$0")
 export xorriso=xorriso
 export image_file=/tmp/xorriso_hardlinks.iso
 export on_disk=/tmp/xorriso_hardlinks_test_dir
-export in_iso="$on_disk"
+export in_iso=""
 export copy_on_disk=/tmp/xorriso_hardlinks_copy_dir
 export keep=0
 export failure=0
 export next_is_xorriso=0
+export next_is_rc=0
 export bad=0
 
+
+config_by_var() {
+  # This is called once before option interpretation, and once for each
+  # option -rc.
+  # Variables get set to empty content to keep them from being applied
+  # more than once and thus overriding settings of higher precedence.
+
+  # >>> The short names are not good.
+  # >>> Environment variables should have a common prefix. Like RELENG_
+  # >>> In general, the names should be a bit more expressive.
+  # >>> Like RELENG_XORRISO
+
+  test -n "$XOR" && xorriso="$XOR" && XOR=
+  test -n "$RELENG_XORRISO" && xorriso="$RELENG_XORRISO" && RELENG_XORRISO=
+
+  test -n "$IMG" && image_file="$IMG" && IMG=
+  test -n "$RELENG_TMPIMAGE" && image_file="$RELENG_TMPIMAGE" \
+                             && RELENG_TMPIMAGE=
+
+  # This is not $DIR, which would exist before and after the test,
+  # but a temporary directory which may not exist before.
+  test -n "$RELENG_TMPDIR" && on_disk="$RELENG_TMPDIR" && RELENG_TMPDIR=
+
+  test -n "$RELENG_ISODIR" && in_iso="$RELENG_ISODIR" && RELENG_ISODIR=
+
+  test -n "$RELENG_TMPCOPYDIR" && copy_on_disk="$RELENG_TMPCOPYDIR" \
+                               && RELENG_TMPCOPYDIR=
+
+}
+
 clean_up() {
   if test "$keep" = 1
   then
@@ -27,20 +58,37 @@ clean_up() {
   fi
 }
 
-skip=0
+
+# Setup
+
+# Interpret a default configuration file here, if the test has one.
+# This one has none.
+
+# >>> Best would be if the configuration file would not override env variables.
+
+# Process env variables and default configfile variables together
+config_by_var
+
+
+# Now interpret program arguments and possibly given config files
 for i in "$@"
 do
   if test "$next_is_xorriso" = 1
   then
     xorriso="$i"
     next_is_xorriso=0
-  elif test "$skip" -gt 0
+  elif test "$next_is_rc" = 1
   then
-    skip=$(expr $skip - 1)
+
+    # >>> This looks darn dangerous. We need a trustworthy config interpreter.
+    # >>> http://www.netjeff.com/humor/item.cgi?file=ShootInFoot-OS
+    . "$i"
+
+    config_by_var
+    next_is_rc=0
   elif test x"$i" = x"-rc"
   then
-    # No configuration yet
-    skip=1
+    next_is_rc=1
   elif test x"$i" = x"-keep"
   then
     keep=1
@@ -58,21 +106,24 @@ do
   fi
 done
 
+test -z "$in_iso" && in_iso="$on_disk"
+
+
 if test -e "$image_file"
 then
-  echo "TEST ENVIRONMENT ERROR: $prog : Existing image_file target:" >&2
+  echo "=== TEST ENVIRONMENT ERROR: $prog : Existing image_file target:" >&2
   ls -ld "$image_file" >&2
   bad=1
 fi
 if test -e "$on_disk"
 then
-  echo "TEST ENVIRONMENT ERROR: $prog : Existing on_disk target:" >&2
+  echo "=== TEST ENVIRONMENT ERROR: $prog : Existing on_disk target:" >&2
   ls -ld "$on_disk" >&2
   bad=1
 fi
 if test -e "$copy_on_disk"
 then
-  echo "TEST ENVIRONMENT ERROR: $prog : Existing copy_on_disk target:" >&2
+  echo "=== TEST ENVIRONMENT ERROR: $prog : Existing copy_on_disk target:" >&2
   ls -ld "$copy_on_disk" >&2
   bad=1
 fi
@@ -93,7 +144,9 @@ ls -l "$on_disk"/*
 
 echo "=== Producing simple image" >&2
 "$xorriso" \
+  -version \
   -for_backup \
+  -padding 0 \
   -outdev "$image_file" \
   -update_r "$on_disk" "$in_iso" \
   -hardlinks perform_update
@@ -110,11 +163,12 @@ echo "=== Copying from image to temporary disk tree" >&2
 ## For testing the test: Let it fail deliberately
 ## rm "$copy_on_disk"/file_1_link_b
 
+
 echo "=== Comparing original disk tree and temporary one" >&2
 diff -r "$on_disk" "$copy_on_disk"
 if test "$?" -ne 0
 then
-  echo "WRONG: diff -r $on_disk $copy_on_disk   reports differences" >&2
+  echo "=== WRONG: diff -r $on_disk $copy_on_disk   reports differences" >&2
   failure=1
 else
   echo "=== OK" >&2
@@ -128,9 +182,9 @@ if test x"$x" = x"$expected"
 then
   echo "=== OK" >&2
 else
-  echo "WRONG: Link count of extracted files is not as expected." >&2
-  echo "Expected:  $expected" >&2
-  echo "Got     :  $x" >&2
+  echo "=== WRONG: Link count of extracted files is not as expected." >&2
+  echo "=== Expected:  $expected" >&2
+  echo "=== Got     :  $x" >&2
   failure=1
 fi
 
@@ -142,9 +196,9 @@ clean_up
 echo 
 if test "$failure" = 1
 then
-  echo "======== $prog :" 'FAILURE !!!'
+  echo "======== $prog :" 'FAILED'
 else
-  echo "======== $prog :" "Success."
+  echo "======== $prog :" "Passed"
 fi
 echo