gh-133439: Fix dot commands with trailing spaces are mistaken for multi-line sqlite statements in the sqlite3 command-line interface (GH-133440)

Lib/sqlite3/__main__.py

@@ -48,14 +48,22 @@ class SqliteInteractiveConsole(InteractiveConsole):
         Return True if more input is needed; buffering is done automatically.
         Return False if input is a complete statement ready for execution.
         """
-        match source:
+        if not source or source.isspace():
-            case ".version":
+            return False
+        if source[0] == ".":
+            match source[1:].strip():
+                case "version":
                     print(f"{sqlite3.sqlite_version}")
-            case ".help":
+                case "help":
                     print("Enter SQL code and press enter.")
-            case ".quit":
+                case "quit":
                     sys.exit(0)
-            case _:
+                case "":
+                    pass
+                case _ as unknown:
+                    self.write("Error: unknown command or invalid arguments:"
+                               f'  "{unknown}".\n')
+        else:
             if not sqlite3.complete_statement(source):
                 return True
             execute(self._cur, source)

Lib/test/test_sqlite3/test_cli.py

@@ -116,6 +116,38 @@ class InteractiveSession(unittest.TestCase):
         self.assertEqual(out.count(self.PS2), 0)
         self.assertIn(sqlite3.sqlite_version, out)
 
+    def test_interact_empty_source(self):
+        out, err = self.run_cli(commands=("", " "))
+        self.assertIn(self.MEMORY_DB_MSG, err)
+        self.assertEndsWith(out, self.PS1)
+        self.assertEqual(out.count(self.PS1), 3)
+        self.assertEqual(out.count(self.PS2), 0)
+
+    def test_interact_dot_commands_unknown(self):
+        out, err = self.run_cli(commands=(".unknown_command", ))
+        self.assertIn(self.MEMORY_DB_MSG, err)
+        self.assertEndsWith(out, self.PS1)
+        self.assertEqual(out.count(self.PS1), 2)
+        self.assertEqual(out.count(self.PS2), 0)
+        self.assertIn("Error", err)
+        # test "unknown_command" is pointed out in the error message
+        self.assertIn("unknown_command", err)
+
+    def test_interact_dot_commands_empty(self):
+        out, err = self.run_cli(commands=("."))
+        self.assertIn(self.MEMORY_DB_MSG, err)
+        self.assertEndsWith(out, self.PS1)
+        self.assertEqual(out.count(self.PS1), 2)
+        self.assertEqual(out.count(self.PS2), 0)
+
+    def test_interact_dot_commands_with_whitespaces(self):
+        out, err = self.run_cli(commands=(".version ", ". version"))
+        self.assertIn(self.MEMORY_DB_MSG, err)
+        self.assertEqual(out.count(sqlite3.sqlite_version + "\n"), 2)
+        self.assertEndsWith(out, self.PS1)
+        self.assertEqual(out.count(self.PS1), 3)
+        self.assertEqual(out.count(self.PS2), 0)
+
     def test_interact_valid_sql(self):
         out, err = self.run_cli(commands=("SELECT 1;",))
         self.assertIn(self.MEMORY_DB_MSG, err)

Misc/NEWS.d/next/Library/2025-05-05-22-11-24.gh-issue-133439.LpmyFz.rst

@@ -0,0 +1,2 @@
+Fix dot commands with trailing spaces are mistaken for multi-line SQL
+statements in the sqlite3 command-line interface.