gh-149495: Fix input assuming the last character being a '\n'

Lib/test/test_builtin.py

@@ -2813,7 +2813,8 @@ def _run_child(self, child, terminal_input):
     def check_input_tty(self, prompt, terminal_input, stdio_encoding=None, *,
                         expected=None,
                         stdin_errors='surrogateescape',
-                        stdout_errors='replace'):
+                        stdout_errors='replace',
+                        terminal_input_end=b'\r\n'):
         if not sys.stdin.isatty() or not sys.stdout.isatty():
             self.skipTest("stdin and stdout must be ttys")
         def child(wpipe):
@@ -2831,7 +2832,7 @@ def child(wpipe):
             except BaseException as e:
                 print(ascii(f'{e.__class__.__name__}: {e!s}'), file=wpipe)
         with self.detach_readline():
-            lines = self.run_child(child, terminal_input + b"\r\n")
+            lines = self.run_child(child, terminal_input + terminal_input_end)
         # Check we did exercise the GNU readline path
         self.assertIn(lines[0], {'tty = True', 'tty = False'})
         if lines[0] != 'tty = True':
@@ -2869,6 +2870,9 @@ def test_input_tty(self):
         # Test input() functionality when wired to a tty
         self.check_input_tty("prompt", b"quux")
 
+    def test_input_tty_eof_without_newline(self):
+        self.check_input_tty("prompt", b"quux", terminal_input_end=b"\x04")
+
     def test_input_tty_non_ascii(self):
         # Check stdin/stdout encoding is used when invoking PyOS_Readline()
         self.check_input_tty("prompté", b"quux\xc3\xa9", "utf-8")

Misc/NEWS.d/next/Core_and_Builtins/2026-05-02-09-43-45.gh-issue-149237.-dY_PV.rst

@@ -0,0 +1 @@
+Fix :func:`input` assuming the last character being a ``'\n'`` and removing it.

Python/bltinmodule.c

@@ -2586,9 +2586,14 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
                 result = NULL;
             }
             else {
-                len--;   /* strip trailing '\n' */
-                if (len != 0 && s[len-1] == '\r')
-                    len--;   /* strip trailing '\r' */
+                /* strip trailing '\n' */
+                if (s[len-1] == '\n') {
+                    len--;
+                }
+                /* strip trailing '\r' */
+                if (len != 0 && s[len-1] == '\r') {
+                    len--;
+                }
                 result = PyUnicode_Decode(s, len, stdin_encoding_str,
                                                   stdin_errors_str);
             }