gh-153731: Handle NUL and lone surrogate in sqlite3 CLI REPL

Lib/sqlite3/__main__.py

@@ -80,7 +80,16 @@ def runsource(self, source, filename="<input>", symbol="single"):
                     self.write(f'{t.type}Error{t.reset}: {t.message}unknown '
                                f'command: "{unknown}"{t.reset}\n')
         else:
-            if not sqlite3.complete_statement(source):
+            try:
+                complete = sqlite3.complete_statement(source)
+            # NUL -> ValueError, lone surrogate -> UnicodeEncodeError; keep
+            # narrow so real bugs still surface.
+            except (ValueError, UnicodeEncodeError) as e:
+                t = theme.traceback
+                self.write(f"{t.type}{type(e).__name__}{t.reset}: "
+                           f"{t.message}{e}{t.reset}\n")
+                return False
+            if not complete:
                 return True
             execute(self._cur, source, theme=theme)
         return False

Lib/test/test_sqlite3/test_cli.py

@@ -189,6 +189,28 @@ def test_interact_invalid_sql(self):
         self.assertEqual(out.count(self.PS1), 2)
         self.assertEqual(out.count(self.PS2), 0)
 
+    def test_interact_null_byte(self):
+        # NUL byte -> ValueError from complete_statement().
+        out, err = self.run_cli(commands=("SELECT '\0';", "SELECT 1;"))
+        self.assertIn(self.MEMORY_DB_MSG, err)
+        self.assertNotIn("Traceback (most recent call last)", err)
+        self.assertIn("ValueError: ", err)
+        self.assertIn("(1,)\n", out)
+        self.assertEndsWith(out, self.PS1)
+        self.assertEqual(out.count(self.PS1), 3)
+        self.assertEqual(out.count(self.PS2), 0)
+
+    def test_interact_lone_surrogate(self):
+        # Lone surrogate -> UnicodeEncodeError from complete_statement().
+        out, err = self.run_cli(commands=("SELECT '\udc80';", "SELECT 1;"))
+        self.assertIn(self.MEMORY_DB_MSG, err)
+        self.assertNotIn("Traceback (most recent call last)", err)
+        self.assertIn("UnicodeEncodeError: ", err)
+        self.assertIn("(1,)\n", out)
+        self.assertEndsWith(out, self.PS1)
+        self.assertEqual(out.count(self.PS1), 3)
+        self.assertEqual(out.count(self.PS2), 0)
+
     def test_interact_on_disk_file(self):
         self.addCleanup(unlink, TESTFN)
 

Misc/NEWS.d/next/Library/2026-07-14-19-41-38.gh-issue-153731.ctLI83.rst

@@ -0,0 +1,4 @@
+Fix the :mod:`sqlite3` command-line interface so that an input line
+containing an embedded null character or a lone surrogate no longer crashes
+the interactive shell; an error is now printed and the shell continues.
+Patch by tonghuaroot.