gh-87868: Sort and remove duplicates in getenvironment() (GH-102731)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Pieter Eendebak <pieter.eendebak@gmail.com>
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 6d3228b..102e697 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -791,6 +791,19 @@ class ProcessTestCase(BaseTestCase):
             stdout, stderr = p.communicate()
             self.assertEqual(stdout, b"orange")
 
+    @unittest.skipUnless(sys.platform == "win32", "Windows only issue")
+    def test_win32_duplicate_envs(self):
+        newenv = os.environ.copy()
+        newenv["fRUit"] = "cherry"
+        newenv["fruit"] = "lemon"
+        newenv["FRUIT"] = "orange"
+        newenv["frUit"] = "banana"
+        with subprocess.Popen(["CMD", "/c", "SET", "fruit"],
+                              stdout=subprocess.PIPE,
+                              env=newenv) as p:
+            stdout, _ = p.communicate()
+            self.assertEqual(stdout.strip(), b"frUit=banana")
+
     # Windows requires at least the SYSTEMROOT environment variable to start
     # Python
     @unittest.skipIf(sys.platform == 'win32',
@@ -822,6 +835,17 @@ class ProcessTestCase(BaseTestCase):
                                if not is_env_var_to_ignore(k)]
             self.assertEqual(child_env_names, [])
 
+    def test_one_environment_variable(self):
+        newenv = {'fruit': 'orange'}
+        cmd = [sys.executable, '-c',
+                               'import sys,os;'
+                               'sys.stdout.write("fruit="+os.getenv("fruit"))']
+        if sys.platform == "win32":
+            cmd = ["CMD", "/c", "SET", "fruit"]
+        with subprocess.Popen(cmd, stdout=subprocess.PIPE, env=newenv) as p:
+            stdout, _ = p.communicate()
+            self.assertTrue(stdout.startswith(b"fruit=orange"))
+
     def test_invalid_cmd(self):
         # null character in the command name
         cmd = sys.executable + '\0'
@@ -862,6 +886,19 @@ class ProcessTestCase(BaseTestCase):
             stdout, stderr = p.communicate()
             self.assertEqual(stdout, b"orange=lemon")
 
+    @unittest.skipUnless(sys.platform == "win32", "Windows only issue")
+    def test_win32_invalid_env(self):
+        # '=' in the environment variable name
+        newenv = os.environ.copy()
+        newenv["FRUIT=VEGETABLE"] = "cabbage"
+        with self.assertRaises(ValueError):
+            subprocess.Popen(ZERO_RETURN_CMD, env=newenv)
+
+        newenv = os.environ.copy()
+        newenv["==FRUIT"] = "cabbage"
+        with self.assertRaises(ValueError):
+            subprocess.Popen(ZERO_RETURN_CMD, env=newenv)
+
     def test_communicate_stdin(self):
         p = subprocess.Popen([sys.executable, "-c",
                               'import sys;'