From e38b43c213a8ab2ad9748bac2732af9b58c816ae Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend@python.org>
Date: Thu, 25 Apr 2024 10:11:45 +0200
Subject: [PATCH] gh-118221: Always use the default row factory in
 sqlite3.iterdump() (#118223)

sqlite3.iterdump() depends on the row factory returning resulting rows
as tuples; it will fail with custom row factories like for example a
dict factory.

With this commit, we explicitly reset the row factory of the cursor used
by iterdump(), so we always get predictable results. This does not
affect the row factory of the parent connection.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
---
 Lib/sqlite3/dump.py                               |  1 +
 Lib/test/test_sqlite3/test_dump.py                | 15 +++++++++++++++
 ...2024-04-24-12-29-33.gh-issue-118221.2k_bac.rst |  2 ++
 3 files changed, 18 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-04-24-12-29-33.gh-issue-118221.2k_bac.rst

diff --git a/Lib/sqlite3/dump.py b/Lib/sqlite3/dump.py
index 9dcce7dc76c..57e6a3b4f1e 100644
--- a/Lib/sqlite3/dump.py
+++ b/Lib/sqlite3/dump.py
@@ -26,6 +26,7 @@ def _iterdump(connection, *, filter=None):
 
     writeable_schema = False
     cu = connection.cursor()
+    cu.row_factory = None  # Make sure we get predictable results.
     # Disable foreign key constraints, if there is any foreign key violation.
     violations = cu.execute("PRAGMA foreign_key_check").fetchall()
     if violations:
diff --git a/Lib/test/test_sqlite3/test_dump.py b/Lib/test/test_sqlite3/test_dump.py
index 7261b7f0dc9..d508f238f84 100644
--- a/Lib/test/test_sqlite3/test_dump.py
+++ b/Lib/test/test_sqlite3/test_dump.py
@@ -190,6 +190,21 @@ class DumpTests(MemoryDatabaseMixin, unittest.TestCase):
         got = list(self.cx.iterdump())
         self.assertEqual(expected, got)
 
+    def test_dump_custom_row_factory(self):
+        # gh-118221: iterdump should be able to cope with custom row factories.
+        def dict_factory(cu, row):
+            fields = [col[0] for col in cu.description]
+            return dict(zip(fields, row))
+
+        self.cx.row_factory = dict_factory
+        CREATE_TABLE = "CREATE TABLE test(t);"
+        expected = ["BEGIN TRANSACTION;", CREATE_TABLE, "COMMIT;"]
+
+        self.cu.execute(CREATE_TABLE)
+        actual = list(self.cx.iterdump())
+        self.assertEqual(expected, actual)
+        self.assertEqual(self.cx.row_factory, dict_factory)
+
     def test_dump_virtual_tables(self):
         # gh-64662
         expected = [
diff --git a/Misc/NEWS.d/next/Library/2024-04-24-12-29-33.gh-issue-118221.2k_bac.rst b/Misc/NEWS.d/next/Library/2024-04-24-12-29-33.gh-issue-118221.2k_bac.rst
new file mode 100644
index 00000000000..9b0ea9978a1
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-04-24-12-29-33.gh-issue-118221.2k_bac.rst
@@ -0,0 +1,2 @@
+Fix a bug where :func:`sqlite3.iterdump` could fail if a custom :attr:`row
+factory <sqlite3.Connection.row_factory>` was used. Patch by Erlend Aasland.