Fix pyrepl overriding printed output without newlines

Author: JanEricNitschke

Lib/_pyrepl/unix_console.py

@@ -235,8 +235,9 @@ def refresh(self, screen, c_xy):
         if not self.__gone_tall:
             while len(self.screen) < min(len(screen), self.height):
                 self.__hide_cursor()
-                self.__move(0, len(self.screen) - 1)
-                self.__write("\n")
+                if self.screen:
+                    self.__move(0, len(self.screen) - 1)
+                    self.__write("\n")
                 self.posxy = 0, len(self.screen)
                 self.screen.append("")
         else:
@@ -785,7 +786,7 @@ def __tputs(self, fmt, prog=delayprog):
         will never do anyone any good."""
         # using .get() means that things will blow up
         # only if the bps is actually needed (which I'm
-        # betting is pretty unlkely)
+        # betting is pretty unlikely)
         bps = ratedict.get(self.__svtermstate.ospeed)
         while True:
             m = prog.search(fmt)

Lib/_pyrepl/windows_console.py

@@ -183,8 +183,9 @@ def refresh(self, screen: list[str], c_xy: tuple[int, int]) -> None:
 
         while len(self.screen) < min(len(screen), self.height):
             self._hide_cursor()
-            self._move_relative(0, len(self.screen) - 1)
-            self.__write("\n")
+            if self.screen:
+                self._move_relative(0, len(self.screen) - 1)
+                self.__write("\n")
             self.posxy = 0, len(self.screen)
             self.screen.append("")
 

Lib/test/test_pyrepl/test_pyrepl.py

@@ -1787,3 +1787,33 @@ def test_detect_pip_usage_in_repl(self):
                     " outside of the Python REPL"
                 )
                 self.assertIn(hint, output)
+
+    @force_not_colorized
+    def test_no_newline(self):
+        env = os.environ.copy()
+        env.pop("PYTHON_BASIC_REPL", "")
+        env["PYTHON_BASIC_REPL"] = "1"
+        expected_output_sequence = "Something pretty long>>> exit()"
+        basic_output, basic_exit_code = self.run_repl("print('Something pretty long', end='')\nexit()\n", env=env)
+        self.assertEqual(basic_exit_code, 0)
+        self.assertIn(expected_output_sequence, basic_output)
+
+        output, exit_code = self.run_repl("print('Something pretty long', end='')\nexit()\n")
+        self.assertEqual(exit_code, 0)
+
+        # Define escape sequences that don't affect cursor position or visual output
+        bracketed_paste_mode = r'\x1b\[\?2004[hl]'  # Enable/disable bracketed paste
+        application_cursor_keys = r'\x1b\[\?1[hl]'   # Enable/disable application cursor keys
+        application_keypad_mode = r'\x1b[=>]'         # Enable/disable application keypad
+        insert_character = r'\x1b\[\d+@'             # Insert character sequences
+        cursor_visibility = r'\x1b\[\?25[hl]'        # Show/hide cursor
+        cursor_blinking = r'\x1b\[\?12[hl]'          # Start/stop cursor blinking
+
+        # Remove only non-visual terminal control sequences (NOT cursor movement)
+        cleaned_output = re.sub(
+            f'{bracketed_paste_mode}|{application_cursor_keys}|{application_keypad_mode}|{insert_character}|{cursor_visibility}|{cursor_blinking}',
+            '',
+            output
+        )
+
+        self.assertIn(expected_output_sequence, cleaned_output)