mode/reduce-tracking: Fix inability to open Gmail when using reduce-t…

…racking-mode.

nyxt.asd

@@ -61,6 +61,7 @@
                plump
                clss
                spinneret
+               split-sequence
                slynk
                slynk/arglists
                slynk/fancy-inspector

source/mode/reduce-tracking.lisp

@@ -56,15 +56,47 @@ still being less noticeable in the crowd.")
     :export nil
     :documentation "The timezone the system had before enabling this mode.")))
 
+;; NB: QURI:URL-ENCODE-PARAMS is not applicable for filtering a
+;; query. For example, when opening Gmail a query may look like
+;; "https://accounts.google.com/ServiceLogin?service=mail&passive=XXXXXX&osid=1&continue=https://mail.google.com"
+;; and quri will percent-encode it to
+;; https://accounts.google.com/ServiceLogin?service=mail&passive=1209600&osid=1&continue=https%3A%2F%2Fmail.google.com
+;; This is incorrect and will result in inability to load the
+;; page. This function does not add an extra level of percent
+;; encoding.
+(serapeum:-> decode-params-lite (string)
+             (values list &optional))
+(defun decode-params-lite (query)
+  (mapcar
+   (alex:curry #'split-sequence:split-sequence #\=)
+   (split-sequence:split-sequence #\& query)))
+
+(serapeum:-> encode-params-lite (list)
+             (values string &optional))
+(defun encode-params-lite (string)
+  (format
+   nil "~{~a~^&~}"
+   (mapcar
+    (alex:curry #'format nil "~{~a~^=~}")
+    string)))
+
+(serapeum:-> url-filter-params (string list)
+             (values string &optional))
+(defun url-filter-params (params forbidden-params)
+  "Accept a query parameters (as a string), remove parameters from a
+black list and return them back as a string."
+  (encode-params-lite
+   (remove-if (rcurry #'member forbidden-params :test #'string-equal)
+              (decode-params-lite params)
+              :key #'first)))
+
 (defun strip-tracking-parameters (request-data)
   (let ((mode (find-submode 'reduce-tracking-mode)))
     (when (and mode (not (uiop:emptyp (quri:uri-query (url request-data)))))
-      (setf (quri:uri-query-params (url request-data))
-            (remove-if (rcurry #'member (query-tracking-parameters mode)
-                                          :test #'string-equal)
-                       (quri:url-decode-params (quri:uri-query (url request-data)) :lenient t)
-                       :key #'first)))
-    request-data))
+      (setf (quri:uri-query (url request-data))
+            (url-filter-params (quri:uri-query (url request-data))
+                               (query-tracking-parameters mode)))))
+  request-data)
 
 (defmethod enable ((mode reduce-tracking-mode) &key)
   (setf (old-timezone mode) (uiop:getenv "TZ")