gh-119102: Fix error being thrown on quit when REPL has TERM=dumb

Lib/_pyrepl/__main__.py

@@ -1,12 +1,10 @@
 import os
 import sys
 
-CAN_USE_PYREPL = sys.platform != "win32"
-
 
 def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
-    global CAN_USE_PYREPL
-    if not CAN_USE_PYREPL:
+    from . import env
+    if not env.IS_PYREPL_SUPPORTED_PLATFORM:
         return sys._baserepl()
 
     startup_path = os.getenv("PYTHONSTARTUP")
@@ -23,7 +21,6 @@ def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
     if not hasattr(sys, "ps2"):
         sys.ps2 = "... "
 
-    run_interactive = None
     try:
         import errno
         if not os.isatty(sys.stdin.fileno()):
@@ -32,16 +29,15 @@ def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
         if err := check():
             raise RuntimeError(err)
         from .simple_interact import run_multiline_interactive_console
-        run_interactive = run_multiline_interactive_console
+        return run_multiline_interactive_console(mainmodule)
     except Exception as e:
         from .trace import trace
         msg = f"warning: can't use pyrepl: {e}"
         trace(msg)
         print(msg, file=sys.stderr)
-        CAN_USE_PYREPL = False
-    if run_interactive is None:
+        env.CAN_USE_PYREPL = False
         return sys._baserepl()
-    return run_interactive(mainmodule)
+
 
 if __name__ == "__main__":
     interactive_console()

Lib/_pyrepl/env.py

@@ -0,0 +1,6 @@
+import sys
+
+IS_PYREPL_SUPPORTED_PLATFORM = sys.platform != "win32"
+
+# Note: This will be updated on REPL startup based on additional checks.
+CAN_USE_PYREPL = IS_PYREPL_SUPPORTED_PLATFORM

Lib/site.py

@@ -523,7 +523,7 @@ def register_readline():
             pass
 
         def write_history():
-            from _pyrepl.__main__ import CAN_USE_PYREPL
+            from _pyrepl.env import CAN_USE_PYREPL
             try:
                 if os.getenv("PYTHON_BASIC_REPL") or not CAN_USE_PYREPL:
                     readline.write_history_file(history)

Lib/test/test_repl.py

@@ -34,8 +34,9 @@ def spawn_repl(*args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, **kw):
 
     # Set TERM=vt100, for the rationale see the comments in spawn_python() of
     # test.support.script_helper.
-    env = kw.setdefault('env', dict(os.environ))
-    env['TERM'] = 'vt100'
+    if "env" not in kw:
+        env = kw.setdefault('env', dict(os.environ))
+        env['TERM'] = 'vt100'
     return subprocess.Popen(cmd_line,
                             executable=sys.executable,
                             text=True,
@@ -198,6 +199,15 @@ def bar(x):
     def test_asyncio_repl_is_ok(self):
         assert_python_ok("-m", "asyncio")
 
+    def test_repl_with_dumb_term_exits_cleanly(self):
+        env = dict(os.environ)
+        env.update({"TERM": "dumb"})
+        p = spawn_repl(env=env)
+        p.stdin.write("quit()\n")
+        output = kill_python(p)
+        self.assertEqual(p.returncode, 0)
+        self.assertNotIn("Exception", output)
+        self.assertNotIn("Traceback", output)
 
 
 class TestInteractiveModeSyntaxErrors(unittest.TestCase):

Misc/NEWS.d/next/Library/2024-05-21-13-06-27.gh-issue-119102.E1k90T.rst

@@ -0,0 +1 @@
+Fix error being thrown on quit() in REPL when TERM is set to dumb