From f2e08aa4ea8653a82a080190088584c07ce6a51a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Sat, 15 Mar 2025 11:33:28 +0100
Subject: [PATCH 1/3] ensure that BROWSER is not set for `test_webbrowser` on
 macOS.

---
 Lib/test/test_webbrowser.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Lib/test/test_webbrowser.py b/Lib/test/test_webbrowser.py
index 870ddd7349f494..4c3ea1cd8df13e 100644
--- a/Lib/test/test_webbrowser.py
+++ b/Lib/test/test_webbrowser.py
@@ -321,7 +321,13 @@ def close(self):
 @unittest.skipUnless(sys.platform == "darwin", "macOS specific test")
 @requires_subprocess()
 class MacOSXOSAScriptTest(unittest.TestCase):
+
     def setUp(self):
+        # Ensure that 'BROWSER' is not set to 'open' or something else.
+        # See: https://github.com/python/cpython/issues/131254.
+        env = self.enterContext(os_helper.EnvironmentVarGuard())
+        env.unset("BROWSER")
+
         support.patch(self, os, "popen", self.mock_popen)
         self.browser = webbrowser.MacOSXOSAScript("default")
 

From 431d8278dff7f5cf711859f770fd348383acb071 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Sat, 15 Mar 2025 11:43:10 +0100
Subject: [PATCH 2/3] fix possible KeyError

---
 Lib/test/test_webbrowser.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_webbrowser.py b/Lib/test/test_webbrowser.py
index 4c3ea1cd8df13e..59b2877078e257 100644
--- a/Lib/test/test_webbrowser.py
+++ b/Lib/test/test_webbrowser.py
@@ -326,7 +326,8 @@ def setUp(self):
         # Ensure that 'BROWSER' is not set to 'open' or something else.
         # See: https://github.com/python/cpython/issues/131254.
         env = self.enterContext(os_helper.EnvironmentVarGuard())
-        env.unset("BROWSER")
+        if "BROWSER" in env:
+            env.unset("BROWSER")
 
         support.patch(self, os, "popen", self.mock_popen)
         self.browser = webbrowser.MacOSXOSAScript("default")

From a32c280bf097fdb3bd816d7ef5d64a97084f7073 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Sun, 16 Mar 2025 14:07:31 +0100
Subject: [PATCH 3/3] Actually, `unset` checks for the existence of the key.

---
 Lib/test/test_webbrowser.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Lib/test/test_webbrowser.py b/Lib/test/test_webbrowser.py
index 59b2877078e257..4c3ea1cd8df13e 100644
--- a/Lib/test/test_webbrowser.py
+++ b/Lib/test/test_webbrowser.py
@@ -326,8 +326,7 @@ def setUp(self):
         # Ensure that 'BROWSER' is not set to 'open' or something else.
         # See: https://github.com/python/cpython/issues/131254.
         env = self.enterContext(os_helper.EnvironmentVarGuard())
-        if "BROWSER" in env:
-            env.unset("BROWSER")
+        env.unset("BROWSER")
 
         support.patch(self, os, "popen", self.mock_popen)
         self.browser = webbrowser.MacOSXOSAScript("default")