[6.0.x] Fixed #36434 -- Preserved unbuffered stdio (-u) in autoreloader child.

Signed-off-by: SaJH <wogur981208@gmail.com>

Backport of 68aae8878ff90dd787db55ecc44ee712525ccdc6 from main.

1 files changed, 13 insertions, 0 deletions

diff --git a/django/utils/autoreload.py b/django/utils/autoreload.py
index c6716215f5..99812979d7 100644
--- a/django/utils/autoreload.py
+++ b/django/utils/autoreload.py
@@ -268,6 +268,19 @@ def trigger_reload(filename):
 
 def restart_with_reloader():
     new_environ = {**os.environ, DJANGO_AUTORELOAD_ENV: "true"}
+    orig = getattr(sys, "orig_argv", ())
+    if any(
+        (arg == "-u")
+        or (
+            arg.startswith("-")
+            and not arg.startswith(("--", "-X", "-W"))
+            and len(arg) > 2
+            and arg[1:].isalpha()
+            and "u" in arg
+        )
+        for arg in orig[1:]
+    ):
+        new_environ.setdefault("PYTHONUNBUFFERED", "1")
     args = get_child_arguments()
     while True:
         p = subprocess.run(args, env=new_environ, close_fds=False)