fix issue where request.args.pop removed parameters inconsistently (#2112)

Co-authored-by: Adam Hopkins <admhpkns@gmail.com>

sanic/request.py

@@ -265,9 +265,12 @@ class Request:
         :type errors: str
         :return: RequestParameters
         """
-        if not self.parsed_args[
-            (keep_blank_values, strict_parsing, encoding, errors)
-        ]:
+        if (
+            keep_blank_values,
+            strict_parsing,
+            encoding,
+            errors,
+        ) not in self.parsed_args:
             if self.query_string:
                 self.parsed_args[
                     (keep_blank_values, strict_parsing, encoding, errors)
@@ -321,9 +324,12 @@ class Request:
         :type errors: str
         :return: list
         """
-        if not self.parsed_not_grouped_args[
-            (keep_blank_values, strict_parsing, encoding, errors)
-        ]:
+        if (
+            keep_blank_values,
+            strict_parsing,
+            encoding,
+            errors,
+        ) not in self.parsed_not_grouped_args:
             if self.query_string:
                 self.parsed_not_grouped_args[
                     (keep_blank_values, strict_parsing, encoding, errors)

tests/test_requests.py

@@ -289,6 +289,17 @@ def test_query_string(app):
     assert request.args.getlist("test1") == ["1"]
     assert request.args.get("test3", default="My value") == "My value"
 
+def test_popped_stays_popped(app):
+    @app.route("/")
+    async def handler(request):
+        return text("OK")
+
+    request, response = app.test_client.get(
+        "/", params=[("test1", "1")]
+    )
+
+    assert request.args.pop("test1") == ["1"]
+    assert "test1" not in request.args
 
 @pytest.mark.asyncio
 async def test_query_string_asgi(app):