From dc1f16c16552ce7acdfdd298a370be8d03964fc7 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sat, 4 Sep 2021 11:29:10 -0400
Subject: [PATCH] remove erroneous None check from _assert_str

Fixed issue in ``URL`` where validation of "drivername" would not
appropriately respond to the ``None`` value where a string were expected.

Fixes: #6983
Change-Id: If546c373a60533779595a9e393ea9a59a9b8a96f
---
 doc/build/changelog/unreleased_14/6983.rst |  6 +++++
 lib/sqlalchemy/engine/url.py               |  3 ---
 test/engine/test_parseconnect.py           | 30 +++++++++++++++++-----
 3 files changed, 29 insertions(+), 10 deletions(-)
 create mode 100644 doc/build/changelog/unreleased_14/6983.rst

diff --git a/doc/build/changelog/unreleased_14/6983.rst b/doc/build/changelog/unreleased_14/6983.rst
new file mode 100644
index 0000000000..2aa31e8eba
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/6983.rst
@@ -0,0 +1,6 @@
+.. change::
+    :tags: bug, engine
+    :tickets: 6983
+
+    Fixed issue in ``URL`` where validation of "drivername" would not
+    appropriately respond to the ``None`` value where a string were expected.
diff --git a/lib/sqlalchemy/engine/url.py b/lib/sqlalchemy/engine/url.py
index b924f1c730..1b96c3c2e1 100644
--- a/lib/sqlalchemy/engine/url.py
+++ b/lib/sqlalchemy/engine/url.py
@@ -154,9 +154,6 @@ class URL(
 
     @classmethod
     def _assert_str(cls, v, paramname):
-        if v is None:
-            return v
-
         if not isinstance(v, compat.string_types):
             raise TypeError("%s must be a string" % paramname)
         return v
diff --git a/test/engine/test_parseconnect.py b/test/engine/test_parseconnect.py
index ea949dfd64..9acedaa852 100644
--- a/test/engine/test_parseconnect.py
+++ b/test/engine/test_parseconnect.py
@@ -16,6 +16,7 @@ from sqlalchemy.testing import is_
 from sqlalchemy.testing import is_false
 from sqlalchemy.testing import is_true
 from sqlalchemy.testing import mock
+from sqlalchemy.testing.assertions import expect_deprecated
 from sqlalchemy.testing.mock import call
 from sqlalchemy.testing.mock import MagicMock
 from sqlalchemy.testing.mock import Mock
@@ -275,20 +276,35 @@ class URLTest(fixtures.TestBase):
             url.make_url("drivername:///?%s" % expected),
         )
 
-    @testing.combinations(
-        "username",
-        "host",
-        "database",
-    )
-    def test_only_str_constructor(self, argname):
+    @testing.combinations("username", "host", "database", argnames="argname")
+    @testing.combinations((35.8), (True,), argnames="value")
+    def test_only_str_constructor(self, argname, value):
         assert_raises_message(
             TypeError,
             "%s must be a string" % argname,
             url.URL.create,
             "somedriver",
-            **{argname: 35.8}
+            **{argname: value}
         )
 
+    @testing.combinations("username", "host", "database", argnames="argname")
+    def test_none_ok(self, argname):
+        u1 = url.URL.create("drivername", **{argname: None})
+        is_(getattr(u1, argname), None)
+
+    @testing.combinations((35.8), (True,), (None,), argnames="value")
+    def test_only_str_drivername_no_none(self, value):
+        assert_raises_message(
+            TypeError, "drivername must be a string", url.URL.create, value
+        )
+
+    @testing.combinations((35.8), (True,), (None,), argnames="value")
+    def test_only_str_drivername_no_none_legacy(self, value):
+        with expect_deprecated(r"Calling URL\(\) directly"):
+            assert_raises_message(
+                TypeError, "drivername must be a string", url.URL, value
+            )
+
     @testing.combinations(
         "username",
         "host",
-- 
2.47.2