fix: handle isatty correctly (#18277) (#18278)

sys.stdin can be `None`

[skip ci]

(cherry picked from commit 35ba00a54e)

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/__init__.py

@@ -453,7 +453,7 @@ def msgprint(
 	if as_list and type(msg) in (list, tuple):
 		out.as_list = 1
 
-	if sys.stdin.isatty():
+	if sys.stdin and sys.stdin.isatty():
 		msg = _strip_html_tags(out.message)
 
 	if flags.print_messages and out.message:

frappe/utils/__init__.py

@@ -560,7 +560,7 @@ def is_cli() -> bool:
 	try:
 		invoked_from_terminal = bool(os.get_terminal_size())
 	except Exception:
-		invoked_from_terminal = sys.stdin.isatty()
+		invoked_from_terminal = sys.stdin and sys.stdin.isatty()
 	return invoked_from_terminal