gh-108590: Fix sqlite3.iterdump for invalid unicode in text columns.

Lib/sqlite3/dump.py

@@ -14,6 +14,24 @@ def _quote_name(name):
 def _quote_value(value):
     return "'{0}'".format(value.replace("'", "''"))
 
+def _force_decode(bs, *args, **kwargs):
+    try:
+        return bs.decode(*args, **kwargs)
+    except UnicodeDecodeError:
+        return "".join([chr(c) for c in bs])
+
+class _ctx_text_factory:
+    def __init__(self, connection, text_factory):
+        self.connection = connection
+        self.text_factory = text_factory
+        self.orig_text_factory = None
+
+    def __enter__(self):
+        self.orig_text_factory = self.connection.text_factory
+        self.connection.text_factory = self.text_factory
+
+    def __exit__(self, type, value, tb):
+        self.connection.text_factory = self.orig_text_factory
 
 def _iterdump(connection):
     """
@@ -74,8 +92,9 @@ def _iterdump(connection):
             )
         )
         query_res = cu.execute(q)
-        for row in query_res:
-            yield("{0};".format(row[0]))
+        with _ctx_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 = """

Lib/test/test_sqlite3/test_dump.py

@@ -133,6 +133,21 @@ 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()

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