gh-128636: Fix crash in PyREPL when os.environ is overwritten with an invalid value...

Signed-off-by: yihong0618 <zouzou0208@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

diff --git a/Lib/_colorize.py b/Lib/_colorize.py
index f45e7b8bb300f1f0699c28f640e75e2c7c97ea43..d35486296f2684307b21e03853800cd9278a70a9 100644 (file)
--- a/Lib/_colorize.py
+++ b/Lib/_colorize.py
@@ -288,21 +288,29 @@ def decolor(text: str) -> str:
 
 
 def can_colorize(*, file: IO[str] | IO[bytes] | None = None) -> bool:
+
+    def _safe_getenv(k: str, fallback: str | None = None) -> str | None:
+        """Exception-safe environment retrieval. See gh-128636."""
+        try:
+            return os.environ.get(k, fallback)
+        except Exception:
+            return fallback
+
     if file is None:
         file = sys.stdout
 
     if not sys.flags.ignore_environment:
-        if os.environ.get("PYTHON_COLORS") == "0":
+        if _safe_getenv("PYTHON_COLORS") == "0":
             return False
-        if os.environ.get("PYTHON_COLORS") == "1":
+        if _safe_getenv("PYTHON_COLORS") == "1":
             return True
-    if os.environ.get("NO_COLOR"):
+    if _safe_getenv("NO_COLOR"):
         return False
     if not COLORIZE:
         return False
-    if os.environ.get("FORCE_COLOR"):
+    if _safe_getenv("FORCE_COLOR"):
         return True
-    if os.environ.get("TERM") == "dumb":
+    if _safe_getenv("TERM") == "dumb":
         return False
 
     if not hasattr(file, "fileno"):
@@ -345,7 +353,8 @@ def get_theme(
     environment (including environment variable state and console configuration
     on Windows) can also change in the course of the application life cycle.
     """
-    if force_color or (not force_no_color and can_colorize(file=tty_file)):
+    if force_color or (not force_no_color and
+                       can_colorize(file=tty_file)):
         return _theme
     return theme_no_color
 

diff --git a/Lib/_pyrepl/unix_console.py b/Lib/_pyrepl/unix_console.py
index a7e49923191c073232374a173cbe46aa23e00c22..9953051bf7c4efbbdbcbb01eac2e5601704b074d 100644 (file)
--- a/Lib/_pyrepl/unix_console.py
+++ b/Lib/_pyrepl/unix_console.py
@@ -159,6 +159,10 @@ class UnixConsole(Console):
         self.pollob.register(self.input_fd, select.POLLIN)
         self.terminfo = terminfo.TermInfo(term or None)
         self.term = term
+        self.is_apple_terminal = (
+            platform.system() == "Darwin"
+            and os.getenv("TERM_PROGRAM") == "Apple_Terminal"
+        )
 
         @overload
         def _my_getstr(cap: str, optional: Literal[False] = False) -> bytes: ...
@@ -339,7 +343,7 @@ class UnixConsole(Console):
         tcsetattr(self.input_fd, termios.TCSADRAIN, raw)
 
         # In macOS terminal we need to deactivate line wrap via ANSI escape code
-        if platform.system() == "Darwin" and os.getenv("TERM_PROGRAM") == "Apple_Terminal":
+        if self.is_apple_terminal:
             os.write(self.output_fd, b"\033[?7l")
 
         self.screen = []
@@ -370,7 +374,7 @@ class UnixConsole(Console):
         self.flushoutput()
         tcsetattr(self.input_fd, termios.TCSADRAIN, self.__svtermstate)
 
-        if platform.system() == "Darwin" and os.getenv("TERM_PROGRAM") == "Apple_Terminal":
+        if self.is_apple_terminal:
             os.write(self.output_fd, b"\033[?7h")
 
         if hasattr(self, "old_sigwinch"):

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index 4bfd01ed14a0a12ea56ef82f68438422a9544051..8d614ab3d42b5a6dcde1feeb32a49ff9c0778e92 100644 (file)
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -2898,7 +2898,7 @@ def force_color(color: bool):
     from .os_helper import EnvironmentVarGuard
 
     with (
-        swap_attr(_colorize, "can_colorize", lambda file=None: color),
+        swap_attr(_colorize, "can_colorize", lambda *, file=None: color),
         EnvironmentVarGuard() as env,
     ):
         env.unset("FORCE_COLOR", "NO_COLOR", "PYTHON_COLORS")

diff --git a/Lib/test/test_pyrepl/test_unix_console.py b/Lib/test/test_pyrepl/test_unix_console.py
index ab1236768cfb3ef66e821b38a5447f9e107611be..6185c7e3c794e374a6827a8fb3c8346a14719ce0 100644 (file)
--- a/Lib/test/test_pyrepl/test_unix_console.py
+++ b/Lib/test/test_pyrepl/test_unix_console.py
@@ -303,3 +303,12 @@ class TestConsole(TestCase):
             self.assertIsInstance(console.getheightwidth(), tuple)
             os.environ = []
             self.assertIsInstance(console.getheightwidth(), tuple)
+
+    @unittest.skipUnless(sys.platform == "darwin", "requires macOS")
+    def test_restore_with_invalid_environ_on_macos(self, _os_write):
+        # gh-128636 for macOS
+        console = UnixConsole(term="xterm")
+        with os_helper.EnvironmentVarGuard():
+            os.environ = []
+            console.prepare()  # needed to call restore()
+            console.restore()  # this should succeed

diff --git a/Misc/NEWS.d/next/Library/2025-09-10-10-02-59.gh-issue-128636.ldRKGZ.rst b/Misc/NEWS.d/next/Library/2025-09-10-10-02-59.gh-issue-128636.ldRKGZ.rst
new file mode 100644 (file)
index 0000000..54eae0a
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-10-10-02-59.gh-issue-128636.ldRKGZ.rst
@@ -0,0 +1,2 @@
+Fix crash in PyREPL when os.environ is overwritten with an invalid value for
+mac