Fix merge-one-file for our-side-added/our-side-removed cases

When commit ed93b449 changed the script so that it does not
touch untracked working tree file, we forgot that we still
needed to resolve the index entry (otherwise they are left
unmerged).
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

git-merge-one-file.sh

@@ -27,8 +27,9 @@ case "${1:-.}${2:-.}${3:-.}" in
 		# read-tree checked that index matches HEAD already,
 		# so we know we do not have this path tracked.
 		# there may be an unrelated working tree file here,
-		# which we should just leave unmolested.
-		exit 0
+		# which we should just leave unmolested.  Make sure
+		# we do not have it in the index, though.
+		exec git update-index --remove -- "$4"
 	fi
 	if test -f "$4"; then
 		rm -f -- "$4" &&
@@ -42,7 +43,8 @@ case "${1:-.}${2:-.}${3:-.}" in
 #
 ".$2.")
 	# the other side did not add and we added so there is nothing
-	# to be done.
+	# to be done, except making the path merged.
+	exec git update-index --add --cacheinfo "$6" "$2" "$4"
 	;;
 "..$3")
 	echo "Adding $4"
@@ -50,7 +52,7 @@ case "${1:-.}${2:-.}${3:-.}" in
 		echo "ERROR: untracked $4 is overwritten by the merge."
 		exit 1
 	}
-	git update-index --add --cacheinfo "$6$7" "$2$3" "$4" &&
+	git update-index --add --cacheinfo "$7" "$3" "$4" &&
 		exec git checkout-index -u -f -- "$4"
 	;;