Update dependencies and vendor (#1761)

vendor/github.com/labstack/echo/v4/echo_fs.go

@@ -0,0 +1,62 @@
+//go:build !go1.16
+// +build !go1.16
+
+package echo
+
+import (
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+)
+
+type filesystem struct {
+}
+
+func createFilesystem() filesystem {
+	return filesystem{}
+}
+
+// Static registers a new route with path prefix to serve static files from the
+// provided root directory.
+func (e *Echo) Static(prefix, root string) *Route {
+	if root == "" {
+		root = "." // For security we want to restrict to CWD.
+	}
+	return e.static(prefix, root, e.GET)
+}
+
+func (common) static(prefix, root string, get func(string, HandlerFunc, ...MiddlewareFunc) *Route) *Route {
+	h := func(c Context) error {
+		p, err := url.PathUnescape(c.Param("*"))
+		if err != nil {
+			return err
+		}
+
+		name := filepath.Join(root, filepath.Clean("/"+p)) // "/"+ for security
+		fi, err := os.Stat(name)
+		if err != nil {
+			// The access path does not exist
+			return NotFoundHandler(c)
+		}
+
+		// If the request is for a directory and does not end with "/"
+		p = c.Request().URL.Path // path must not be empty.
+		if fi.IsDir() && p[len(p)-1] != '/' {
+			// Redirect to ends with "/"
+			return c.Redirect(http.StatusMovedPermanently, p+"/")
+		}
+		return c.File(name)
+	}
+	// Handle added routes based on trailing slash:
+	// 	/prefix  => exact route "/prefix" + any route "/prefix/*"
+	// 	/prefix/ => only any route "/prefix/*"
+	if prefix != "" {
+		if prefix[len(prefix)-1] == '/' {
+			// Only add any route for intentional trailing slash
+			return get(prefix+"*", h)
+		}
+		get(prefix, h)
+	}
+	return get(prefix+"/*", h)
+}