Remove script path in PlatformTests

CHANGES.txt

@@ -124,6 +124,7 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
     - Cleaned up dblite module (checker warnings, etc.).
     - Some cleanup in the FortranCommon tool.
     - Changed the message about scons -H to clarify it shows built-in options.
+    - Fix platform unit test on Windows for Py 3.12+. Fixes #4376.
 
   From Jonathon Reinhart:
     - Fix another instance of `int main()` in CheckLib() causing failures

SCons/Platform/PlatformTests.py

@@ -21,6 +21,15 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+# TODO: issue #4376: since Python 3.12, CPython's posixpath.py does a test
+#   import of 'posix', expecting it to fail on win32. However, if
+#   SCons/Platform is in sys.path, it will find our posix module instead.
+#   This happens in this unittest, since it's the script path. Remove
+#   it before the stdlib imports. Better way to handle this problem?
+import sys
+if 'Platform' in sys.path[0]:
+    platpath = sys.path.pop(0)
+# pylint: disable=wrong-import-position
 import collections
 import unittest
 import os
@@ -30,6 +39,7 @@
 import SCons.Platform
 import SCons.Environment
 import SCons.Action
+# pylint: enable=wrong-import-position
 
 
 class Environment(collections.UserDict):
@@ -130,7 +140,7 @@ def test_Platform(self) -> None:
 
         env = Environment()
         SCons.Platform.Platform()(env)
-        assert env != {}, env
+        assert env, env
 
     def test_win32_no_arch_shell_variables(self) -> None:
         """
@@ -143,9 +153,9 @@ def test_win32_no_arch_shell_variables(self) -> None:
         PA_6432 = os.environ.get('PROCESSOR_ARCHITEW6432')
         PA = os.environ.get('PROCESSOR_ARCHITECTURE')
         if PA_6432:
-            del(os.environ['PROCESSOR_ARCHITEW6432'])
+            del os.environ['PROCESSOR_ARCHITEW6432']
         if PA:
-            del(os.environ['PROCESSOR_ARCHITECTURE'])
+            del os.environ['PROCESSOR_ARCHITECTURE']
 
         p = SCons.Platform.win32.get_architecture()
 
@@ -301,17 +311,16 @@ def __init__(self) -> None:
 
 class PlatformEscapeTestCase(unittest.TestCase):
     def test_posix_escape(self) -> None:
-        """  Check that paths with parens are escaped properly
-        """
-        import SCons.Platform.posix
+        """Check that paths with parens are escaped properly."""
+        from SCons.Platform.posix import escape  # pylint: disable=import-outside-toplevel
 
         test_string = "/my (really) great code/main.cpp"
-        output = SCons.Platform.posix.escape(test_string)
+        output = escape(test_string)
 
         # We expect the escape function to wrap the string
         # in quotes, but not escape any internal characters
         # in the test_string. (Parens doesn't require shell
-        # escaping if their quoted)
+        # escaping if they are quoted)
         assert output[1:-1] == test_string