fix(webdav): make sure Mtime after Ctime (#6372 close #6371)

* fix(server/webdav) make sure Mtime >= Ctime

* fix(server/webdav) avoid variable 'stream' collides with imported package name

server/webdav/util.go

@@ -8,16 +8,21 @@ import (
 )
 
 func (h *Handler) getModTime(r *http.Request) time.Time {
-	return h.getHeaderTime(r, "X-OC-Mtime")
+	return h.getHeaderTime(r, "X-OC-Mtime", "")
 }
 
-// owncloud/ nextcloud haven't impl this, but we can add the support since rclone may support this soon
+// owncloud/ nextcloud haven't impl this, but we can add the support since rclone may support this soon.
+// try ModTime if CreateTime not found in header
 func (h *Handler) getCreateTime(r *http.Request) time.Time {
-	return h.getHeaderTime(r, "X-OC-Ctime")
+	return h.getHeaderTime(r, "X-OC-Ctime", "X-OC-Mtime")
 }
 
-func (h *Handler) getHeaderTime(r *http.Request, header string) time.Time {
+func (h *Handler) getHeaderTime(r *http.Request, header, alternative string) time.Time {
 	hVal := r.Header.Get(header)
+	// try alternative
+	if hVal == "" && alternative != "" {
+		hVal = r.Header.Get(alternative)
+	}
 	if hVal != "" {
 		modTimeUnix, err := strconv.ParseInt(hVal, 10, 64)
 		if err == nil {

server/webdav/webdav.go

@@ -331,21 +331,21 @@ func (h *Handler) handlePut(w http.ResponseWriter, r *http.Request) (status int,
 		Modified: h.getModTime(r),
 		Ctime:    h.getCreateTime(r),
 	}
-	stream := &stream.FileStream{
+	fsStream := &stream.FileStream{
 		Obj:      &obj,
 		Reader:   r.Body,
 		Mimetype: r.Header.Get("Content-Type"),
 	}
-	if stream.Mimetype == "" {
-		stream.Mimetype = utils.GetMimeType(reqPath)
+	if fsStream.Mimetype == "" {
+		fsStream.Mimetype = utils.GetMimeType(reqPath)
 	}
-	err = fs.PutDirectly(ctx, path.Dir(reqPath), stream)
+	err = fs.PutDirectly(ctx, path.Dir(reqPath), fsStream)
 	if errs.IsNotFoundError(err) {
 		return http.StatusNotFound, err
 	}
 
 	_ = r.Body.Close()
-	_ = stream.Close()
+	_ = fsStream.Close()
 	// TODO(rost): Returning 405 Method Not Allowed might not be appropriate.
 	if err != nil {
 		return http.StatusMethodNotAllowed, err