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

Lib/sqlite3/__main__.py

@@ -24,19 +24,25 @@ def execute(c, sql, suppress_errors=True, theme=theme_no_color):
     'sql' is the SQL string to execute.
     """
 
-    try:
-        for row in c.execute(sql):
-            print(row)
-    except sqlite3.Error as e:
+    error = None
+    if "\0" in sql:
+        # A NUL makes c.execute() raise a broad ValueError; pre-check it.
+        error = ValueError("embedded null character")
+    else:
+        try:
+            for row in c.execute(sql):
+                print(row)
+        except (sqlite3.Error, UnicodeEncodeError) as e:  # or a lone surrogate
+            error = e
+    if error is not None:
         t = theme.traceback
-        tp = type(e).__name__
+        tp = type(error).__name__
         try:
-            tp += f" ({e.sqlite_errorname})"
+            tp += f" ({error.sqlite_errorname})"
         except AttributeError:
             pass
-        print(
-            f"{t.type}{tp}{t.reset}: {t.message}{e}{t.reset}", file=sys.stderr
-        )
+        print(f"{t.type}{tp}{t.reset}: {t.message}{error}{t.reset}",
+              file=sys.stderr)
         if not suppress_errors:
             sys.exit(1)
 
@@ -80,7 +86,22 @@ 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):
+            error = None
+            if "\0" in source:
+                # A NUL makes complete_statement() raise a broad ValueError;
+                # pre-check it so ValueError from other code still surfaces.
+                error = ValueError("embedded null character")
+            else:
+                try:
+                    complete = sqlite3.complete_statement(source)
+                except UnicodeEncodeError as e:  # a lone surrogate
+                    error = e
+            if error is not None:
+                t = theme.traceback
+                self.write(f"{t.type}{type(error).__name__}{t.reset}: "
+                           f"{t.message}{error}{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

@@ -69,6 +69,16 @@ def test_cli_execute_incomplete_sql(self):
         stderr = self.expect_failure(":memory:", "sel")
         self.assertIn("OperationalError (SQLITE_ERROR)", stderr)
 
+    def test_cli_execute_null_byte(self):
+        stderr = self.expect_failure(":memory:", "SELECT '\0';")
+        self.assertNotIn("Traceback (most recent call last)", stderr)
+        self.assertIn("ValueError: ", stderr)
+
+    def test_cli_execute_lone_surrogate(self):
+        stderr = self.expect_failure(":memory:", "SELECT '\udc80';")
+        self.assertNotIn("Traceback (most recent call last)", stderr)
+        self.assertIn("UnicodeEncodeError: ", stderr)
+
     def test_cli_on_disk_db(self):
         self.addCleanup(unlink, TESTFN)
         out = self.expect_success(TESTFN, "create table t(t)")
@@ -189,6 +199,28 @@ 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.