Uri extension set for specific types only rather than all

system/src/Grav/Common/Uri.php

@@ -82,7 +82,7 @@ class Uri
 
         // remove the extension if there is one set
         $parts = pathinfo($uri);
-        if (strpos($parts['basename'], '.')) {
+        if (preg_match("/\.(txt|xml|html|json|rss|atom)$/", $parts['basename'])) {
             $uri = rtrim($parts['dirname'], '/').'/'.$parts['filename'];
             $this->extension = $parts['extension'];
         }