--- contrib/python/Werkzeug/py3/werkzeug/sansio/request.py	(index)
+++ contrib/python/Werkzeug/py3/werkzeug/sansio/request.py	(working tree)
@@ -204,6 +204,28 @@ class Request:
         return f"{self.path}?{_to_str(self.query_string, self.url_charset)}"
 
     @property
+    def is_xhr(self):
+        """True if the request was triggered via a JavaScript XMLHttpRequest.
+        This only works with libraries that support the ``X-Requested-With``
+        header and set it to "XMLHttpRequest".  Libraries that do that are
+        prototype, jQuery and Mochikit and probably some more.
+        .. deprecated:: 0.13
+            ``X-Requested-With`` is not standard and is unreliable. You
+            may be able to use :attr:`AcceptMixin.accept_mimetypes`
+            instead.
+        """
+        import warnings
+        warnings.warn(
+            "'Request.is_xhr' is deprecated as of version 0.13 and will"
+            " be removed in version 1.0. The 'X-Requested-With' header"
+            " is not standard and is unreliable. You may be able to use"
+            " 'accept_mimetypes' instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.environ.get("HTTP_X_REQUESTED_WITH", "").lower() == "xmlhttprequest"
+
+    @property
     def is_secure(self) -> bool:
         """``True`` if the request was made with a secure protocol
         (HTTPS or WSS).