Return 0 when there is no error (Golang)

Former-commit-id: e7c4248761e085dd763c7d2fb93e3b364d46cc1f [formerly 59e9b4ed8b656dc61119e7c758fb47ee30c36ad6] [formerly 4e5e9413d14ec8ee0a3a2abbee7f607b15910315 [formerly b214fdd0ebe2bb564cbe64a12dbac725bc4d3f66]]
Former-commit-id: 1dc992ecd0b0169e66f854083554ae825ffa3ddf [formerly 65f85346c9875abcaaa0fa97fa8689ebea774f37]
Former-commit-id: aac3de2cf26430814b9db7073b42f5791ff2a566

http.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strings"
 )
 
@@ -125,6 +126,87 @@ func serveHTTP(c *requestContext, w http.ResponseWriter, r *http.Request) (int,
 	return http.StatusNotImplemented, nil
 }
 
+// serveWebDAV handles the webDAV route of the File Manager.
+func serveWebDAV(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	var err error
+
+	// Checks for user permissions relatively to this path.
+	if !c.us.Allowed(strings.TrimPrefix(r.URL.Path, c.fm.webDavURL)) {
+		return http.StatusForbidden, nil
+	}
+
+	switch r.Method {
+	case "GET", "HEAD":
+		// Excerpt from RFC4918, section 9.4:
+		//
+		// 		GET, when applied to a collection, may return the contents of an
+		//		"index.html" resource, a human-readable view of the contents of
+		//		the collection, or something else altogether.
+		//
+		// It was decided on https://github.com/hacdias/caddy-filemanager/issues/85
+		// that GET, for collections, will return the same as PROPFIND method.
+		path := strings.Replace(r.URL.Path, c.fm.webDavURL, "", 1)
+		path = c.us.scope + "/" + path
+		path = filepath.Clean(path)
+
+		var i os.FileInfo
+		i, err = os.Stat(path)
+		if err != nil {
+			// Is there any error? WebDav will handle it... no worries.
+			break
+		}
+
+		if i.IsDir() {
+			r.Method = "PROPFIND"
+
+			if r.Method == "HEAD" {
+				w = newResponseWriterNoBody(w)
+			}
+		}
+	case "PROPPATCH", "MOVE", "PATCH", "PUT", "DELETE":
+		if !c.us.AllowEdit {
+			return http.StatusForbidden, nil
+		}
+	case "MKCOL", "COPY":
+		if !c.us.AllowNew {
+			return http.StatusForbidden, nil
+		}
+	}
+
+	// Preprocess the PUT request if it's the case
+	if r.Method == http.MethodPut {
+		if err = c.fm.BeforeSave(r, c.fm, c.us); err != nil {
+			return http.StatusInternalServerError, err
+		}
+
+		if put(c, w, r) != nil {
+			return http.StatusInternalServerError, err
+		}
+	}
+
+	c.fm.handler.ServeHTTP(w, r)
+	if err = c.fm.AfterSave(r, c.fm, c.us); err != nil {
+		return http.StatusInternalServerError, err
+	}
+
+	return 0, nil
+}
+
+// serveChecksum calculates the hash of a file. Supports MD5, SHA1, SHA256 and SHA512.
+func serveChecksum(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	query := r.URL.Query().Get("checksum")
+
+	val, err := c.fi.Checksum(query)
+	if err == errInvalidOption {
+		return http.StatusBadRequest, err
+	} else if err != nil {
+		return http.StatusInternalServerError, err
+	}
+
+	w.Write([]byte(val))
+	return 0, nil
+}
+
 // responseWriterNoBody is a wrapper used to suprress the body of the response
 // to a request. Mainly used for HEAD requests.
 type responseWriterNoBody struct {