fixed empty header in markdown

zs.go

@@ -32,7 +32,9 @@ func split2(s, delim string) (string, string) {
 
 func md(s string) (map[string]string, string) {
 	v := map[string]string{}
-	// FIXME: if no header?
+	if strings.Index(s, "\n\n") == -1 {
+		return map[string]string{}, s
+	}
 	header, body := split2(s, "\n\n")
 	for _, line := range strings.Split(header, "\n") {
 		key, value := split2(line, ":")

zs_test.go

@@ -46,6 +46,18 @@ this: is a content`)
 	if body != "this: is a content" {
 		t.Error(body)
 	}
+
+	// Test empty md
+	v, body = md("")
+	if len(v) != 0 || len(body) != 0 {
+		t.Error(v, body)
+	}
+
+	// Test empty header
+	v, body = md("Hello")
+	if len(v) != 0 || body != "Hello" {
+		t.Error(v, body)
+	}
 }
 
 func TestRender(t *testing.T) {