From e2915601a41fb20ebe289d54e5ee3715b9136ec3 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 5 Aug 2023 11:37:39 +0530
Subject: [PATCH] More robust stdio forwarding in tests

---
 kitty_tests/__init__.py | 26 +++++++++++++++++++-------
 kitty_tests/main.py     |  4 +++-
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/kitty_tests/__init__.py b/kitty_tests/__init__.py
index e01e7b0ad..feb146587 100644
--- a/kitty_tests/__init__.py
+++ b/kitty_tests/__init__.py
@@ -11,6 +11,7 @@ import struct
 import sys
 import termios
 import time
+from contextlib import contextmanager
 from pty import CHILD, STDIN_FILENO, STDOUT_FILENO, fork
 from unittest import TestCase
 
@@ -200,6 +201,23 @@ class BaseTest(TestCase):
             c1.x, c1.y, c2.x, c2.y = x1, y1, x2, y2
 
 
+debug_stdout = debug_stderr = -1
+
+
+@contextmanager
+def forwardable_stdio():
+    debug_stdout = fd = os.dup(sys.stdout.fileno())
+    os.set_inheritable(fd, True)
+    debug_stderr = fd = os.dup(sys.stderr.fileno())
+    os.set_inheritable(fd, True)
+    try:
+        yield
+    finally:
+        os.close(debug_stderr)
+        os.close(debug_stdout)
+        debug_stderr = debug_stdout = -1
+
+
 class PTY:
 
     def __init__(
@@ -214,16 +232,10 @@ class PTY:
             from kitty.child import openpty
             self.master_fd, self.slave_fd = openpty()
         else:
-            forwarded_fd = STDOUT_FILENO + 2
-            os.dup2(sys.stdout.fileno(), forwarded_fd)
-            os.dup2(sys.stderr.fileno(), forwarded_fd+1)
             self.child_pid, self.master_fd = fork()
             self.is_child = self.child_pid == CHILD
             if self.is_child:
-                os.environ['KITTY_STDIO_FORWARDED'] = str(forwarded_fd)
-            else:
-                os.close(forwarded_fd)
-                os.close(forwarded_fd + 1)
+                os.environ['KITTY_STDIO_FORWARDED'] = str(debug_stdout)
         self.child_waited_for = False
         if self.is_child:
             while read_screen_size().width != columns * cell_width:
diff --git a/kitty_tests/main.py b/kitty_tests/main.py
index 9ff587b83..f012cd63d 100644
--- a/kitty_tests/main.py
+++ b/kitty_tests/main.py
@@ -113,7 +113,9 @@ def run_cli(suite: unittest.TestSuite, verbosity: int = 4) -> bool:
     r.resultclass = unittest.TextTestResult
     runner = r(verbosity=verbosity)
     runner.tb_locals = True  # type: ignore
-    result = runner.run(suite)
+    from . import forwardable_stdio
+    with forwardable_stdio():
+        result = runner.run(suite)
     return result.wasSuccessful()