Try to fix path if signature is invalid

fix_path.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var fixPathRe = regexp.MustCompile(`/plain/(\S+)\:/([^/])`)
+
+func fixPath(path string) string {
+	for _, match := range fixPathRe.FindAllStringSubmatch(path, -1) {
+		repl := fmt.Sprintf("/plain/%s://", match[1])
+		if match[1] == "local" {
+			repl += "/"
+		}
+		repl += match[2]
+		path = strings.Replace(path, match[0], repl, 1)
+	}
+
+	return path
+}