From 805b2fdca1ff0f3ea9c5986b67e0e2492cdfd5de Mon Sep 17 00:00:00 2001
From: Corvin <corvin@corvin.dev>
Date: Wed, 30 Aug 2023 05:06:21 -0400
Subject: [PATCH] [3.12] gh-108590: Fix sqlite3.iterdump for invalid Unicode in
 TEXT columns (GH-108657)

Co-authored-by: Erlend E. Aasland <erlend@python.org>.
(cherry picked from commit 400a1cebc743515e40157ed7af86e48d654290ce)

Co-authored-by: Corvin <corvin@corvin.dev>
---
 Lib/sqlite3/dump.py                           | 27 +++++++++++++++++--
 Lib/test/test_sqlite3/test_dump.py            | 15 +++++++++++
 ...-08-29-22-53-48.gh-issue-108590.6k0pOl.rst |  1 +
 3 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2023-08-29-22-53-48.gh-issue-108590.6k0pOl.rst

diff --git a/Lib/sqlite3/dump.py b/Lib/sqlite3/dump.py
index 1cf8759f8970f1..cd5fd79258555f 100644
--- a/Lib/sqlite3/dump.py
+++ b/Lib/sqlite3/dump.py
@@ -7,6 +7,28 @@
 # future enhancements, you should normally quote any identifier that
 # is an English language word, even if you do not have to."
 
+
+from contextlib import contextmanager
+
+
+def _force_decode(bs, *args, **kwargs):
+    # gh-108590: Don't fail if the database contains invalid Unicode data.
+    try:
+        return bs.decode(*args, **kwargs)
+    except UnicodeDecodeError:
+        return "".join([chr(c) for c in bs])
+
+
+@contextmanager
+def _text_factory(con, factory):
+    saved_factory = con.text_factory
+    con.text_factory = factory
+    try:
+        yield
+    finally:
+        con.text_factory = saved_factory
+
+
 def _iterdump(connection):
     """
     Returns an iterator to the dump of the database in an SQL text format.
@@ -63,8 +85,9 @@ def _iterdump(connection):
             table_name_ident,
             ",".join("""'||quote("{0}")||'""".format(col.replace('"', '""')) for col in column_names))
         query_res = cu.execute(q)
-        for row in query_res:
-            yield("{0};".format(row[0]))
+        with _text_factory(connection, bytes):
+            for row in query_res:
+                yield("{0};".format(_force_decode(row[0])))
 
     # Now when the type is 'index', 'trigger', or 'view'
     q = """
diff --git a/Lib/test/test_sqlite3/test_dump.py b/Lib/test/test_sqlite3/test_dump.py
index c3ed3aefef0445..3f6de925368e9e 100644
--- a/Lib/test/test_sqlite3/test_dump.py
+++ b/Lib/test/test_sqlite3/test_dump.py
@@ -137,6 +137,21 @@ def test_dump_virtual_tables(self):
         actual = list(self.cx.iterdump())
         self.assertEqual(expected, actual)
 
+    def test_dump_unicode_invalid(self):
+        # gh-108590
+        expected = [
+            "BEGIN TRANSACTION;",
+            "CREATE TABLE foo (data TEXT);",
+            "INSERT INTO \"foo\" VALUES('a\x9f');",
+            "COMMIT;",
+        ]
+        self.cu.executescript("""
+            CREATE TABLE foo (data TEXT);
+            INSERT INTO foo VALUES (CAST(X'619f' AS TEXT));
+        """)
+        actual = list(self.cx.iterdump())
+        self.assertEqual(expected, actual)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2023-08-29-22-53-48.gh-issue-108590.6k0pOl.rst b/Misc/NEWS.d/next/Library/2023-08-29-22-53-48.gh-issue-108590.6k0pOl.rst
new file mode 100644
index 00000000000000..50b41f2a94d9be
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-08-29-22-53-48.gh-issue-108590.6k0pOl.rst
@@ -0,0 +1 @@
+Fixed an issue where :meth:`sqlite3.Connection.iterdump` would fail and leave an incomplete SQL dump if a table includes invalid Unicode sequences. Patch by Corvin McPherson