Fix ensureParent method to correctly construct MKCOL URLs for empty paths

go_cloud/internal/storage/webdav.go

@@ -55,7 +55,12 @@ func (c *WebDAVClient) ensureParent(ctx context.Context, remotePath string) erro
 	cur := c.basePrefix
 	for _, p := range parts {
 		cur = path.Join(cur, p)
-		mkurl := fmt.Sprintf("%s%s", c.baseURL, cur)
+		var mkurl string
+		if cur == "" || cur == "/" {
+			mkurl = fmt.Sprintf("%s/%s", c.baseURL, url.PathEscape(p))
+		} else {
+			mkurl = fmt.Sprintf("%s%s", c.baseURL, cur)
+		}
 		req, _ := http.NewRequestWithContext(ctx, "MKCOL", mkurl, nil)
 		if c.user != "" {
 			req.SetBasicAuth(c.user, c.pass)