diff --git a/filters/syntax-highlighting.sh b/filters/syntax-highlighting.sh
index 6283ce9..5fcc9c9 100755
--- a/filters/syntax-highlighting.sh
+++ b/filters/syntax-highlighting.sh
@@ -42,4 +42,32 @@ EXTENSION="${BASENAME##*.}"
 # map Makefile and Makefile.* to .mk
 [ "${BASENAME%%.*}" == "Makefile" ] && EXTENSION=mk
 
+# highlight versions 2 and 3 have different commandline options. Specifically,
+# the -X option that is used for version 2 is replaced by the -O xhtml option
+# for version 3.
+#
+# Version 2 can be found (for example) on EPEL 5, while version 3 can be
+# found (for example) on EPEL 6.
+#
+# This is for version 2
 exec highlight --force -f -I -X -S $EXTENSION 2>/dev/null
+
+# This is for version 3
+#
+# On CentOS 6.2 (using highlight from EPEL), when highlight doesn't know about
+# an EXTENSION, it outputs a lua error and _no_ text, even when the --force
+# option is used.
+#
+# Also see the bug reports at:
+# http://sourceforge.net/tracker/?func=detail&aid=3490017&group_id=215618&atid=1034391
+# https://bugzilla.redhat.com/show_bug.cgi?id=795567
+#
+# This workaround can be removed when the bug is fixed upstream and the new
+# version is packaged in most distributions.
+#
+# The workaround is to set the extension to 'txt' (plain text) when highlight
+# exits with an error (doesn't know the format).
+#
+#echo "test" | highlight -f -I -O xhtml -S $EXTENSION &>/dev/null
+#[ ${?} -ne 0 ] && EXTENSION="txt"
+#exec highlight --force -f -I -O xhtml -S $EXTENSION 2>/dev/null
diff --git a/tests/setup.sh b/tests/setup.sh
index b21908d..e3c6c17 100755
--- a/tests/setup.sh
+++ b/tests/setup.sh
@@ -22,7 +22,7 @@ mkrepo() {
 	count=$2
 	dir=$PWD
 	test -d "$name" && return
-	printf "Creating testrepo %s\n" $name
+	printf "Creating testrepo %s\n" "$name"
 	mkdir -p "$name"
 	cd "$name"
 	git init
@@ -41,7 +41,7 @@ mkrepo() {
 		git commit -m "add a+b"
 		git branch "1+2"
 	fi
-	cd $dir
+	cd "$dir"
 }
 
 setup_repos()
diff --git a/tests/t0108-patch.sh b/tests/t0108-patch.sh
index e608104..6ee70b3 100755
--- a/tests/t0108-patch.sh
+++ b/tests/t0108-patch.sh
@@ -25,7 +25,7 @@ run_test 'find `cgit` signature' '
 '
 
 run_test 'find initial commit' '
-	root=$(git --git-dir=$PWD/trash/repos/foo/.git rev-list HEAD | tail -1)
+	root=$(git --git-dir="$PWD/trash/repos/foo/.git" rev-list HEAD | tail -1)
 '
 
 run_test 'generate patch for initial commit' '