From ece8186ae230d7928980f1aa3fd8726668505077 Mon Sep 17 00:00:00 2001
From: tonghuaroot <tonghuaroot@gmail.com>
Date: Tue, 14 Jul 2026 19:42:26 +0800
Subject: [PATCH] gh-153731: Handle NUL and lone surrogate in sqlite3 CLI REPL

---
 Lib/sqlite3/__main__.py                       | 11 +++++++++-
 Lib/test/test_sqlite3/test_cli.py             | 22 +++++++++++++++++++
 ...-07-14-19-41-38.gh-issue-153731.ctLI83.rst |  4 ++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2026-07-14-19-41-38.gh-issue-153731.ctLI83.rst

diff --git a/Lib/sqlite3/__main__.py b/Lib/sqlite3/__main__.py
index ec72c6943907175..ca04eb9ccc4469e 100644
--- a/Lib/sqlite3/__main__.py
+++ b/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
diff --git a/Lib/test/test_sqlite3/test_cli.py b/Lib/test/test_sqlite3/test_cli.py
index 1fc0236780fa8ba..c8044e1341f2399 100644
--- a/Lib/test/test_sqlite3/test_cli.py
+++ b/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)
 
diff --git a/Misc/NEWS.d/next/Library/2026-07-14-19-41-38.gh-issue-153731.ctLI83.rst b/Misc/NEWS.d/next/Library/2026-07-14-19-41-38.gh-issue-153731.ctLI83.rst
new file mode 100644
index 000000000000000..cb7ca4eea8e99d9
--- /dev/null
+++ b/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.