2 files changed, 27 insertions, 2 deletions
diff --git a/skate/zippy.go b/skate/zippy.go
index 76f576d..ad1923a 100644
--- a/skate/zippy.go
+++ b/skate/zippy.go
@@ -133,10 +133,10 @@ func ZippyVerifyRefs(releases, refs io.Reader, w io.Writer) error {
 }
 
 // makeKeyFunc creates a function that can be used as keyFunc, selecting a
-// column from sep.
+// column from fields separated by sep; column is 1-indexed.
 func makeKeyFunc(sep string, column int) func(string) (string, error) {
 	return func(s string) (string, error) {
-		if k := lineColumn(s, "\t", 2); k == "" {
+		if k := lineColumn(s, sep, column); k == "" {
 			return k, fmt.Errorf("cannot get key: %s", s)
 		} else {
 			return k, nil
diff --git a/skate/zippy_test.go b/skate/zippy_test.go
new file mode 100644
index 0000000..49f4a54
--- /dev/null
+++ b/skate/zippy_test.go
@@ -0,0 +1,25 @@
+package skate
+
+import "testing"
+
+func TestLineColumn(t *testing.T) {
+	var cases = []struct {
+		line   string
+		sep    string
+		column int
+		result string
+	}{
+		{"", "", 2, ""},
+		{"1 2 3", " ", 1, "1"},
+		{"1 2 3", " ", 2, "2"},
+		{"1 2 3", " ", 3, "3"},
+		{"1 2 3", " ", 4, ""},
+		{"1 2 3", "\t", 1, "1 2 3"},
+	}
+	for _, c := range cases {
+		result := lineColumn(c.line, c.sep, c.column)
+		if result != c.result {
+			t.Fatalf("got %v, want %v", result, c.result)
+		}
+	}
+}