This will make it easier for a future commit to convert a relative
orderfile pathname to either absolute or relative to the top-level
directory.  It also improves code readability.

Signed-off-by: Richard Hansen <hansenr@google.com>
---
 git-mergetool.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-mergetool.sh b/git-mergetool.sh
index e52b4e4f2..b506896dc 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -421,7 +421,7 @@ main () {
 			prompt=true
 			;;
 		-O*)
-			orderfile="$1"
+			orderfile="${1#-O}"
 			;;
 		--)
 			shift
@@ -465,7 +465,7 @@ main () {
 
 	files=$(git -c core.quotePath=false \
 		diff --name-only --diff-filter=U \
-		${orderfile:+"$orderfile"} -- "$@")
+		${orderfile:+"-O$orderfile"} -- "$@")
 
 	cd_to_toplevel
 
-- 
2.11.0.390.gc69c2f50cf-goog