+if [ -z "$diffopts" ]; then
+ diffopts="-u"
+fi
+
+case "$1" in
+*..*) cmd1="stg diff $subdiffopts -r" ;;
+*) cmd1="stg show $subdiffopts" ;;
+esac
+case "$2" in
+*..*) cmd2="stg diff $subdiffopts -r" ;;
+*) cmd2="stg show $subdiffopts" ;;
+esac
+
+colordiff $diffopts \
+ -I '^index [0-9a-b]*..[0-9a-b]*' \
+ -I '^@@ .* @@' \
+ <($cmd1 "$1") <($cmd2 "$2") | less -RFX