run-tests: configure the environment to expand `~` properly with Windows py38+

This was causing tests to point to the actual home path on the system, not the
test defined one.

Differential Revision: https://phab.mercurial-scm.org/D9558

tests/run-tests.py

@@ -1335,6 +1335,9 b' class Test(unittest.TestCase):'
         env['TESTTMP'] = _bytes2sys(self._testtmp)
         env['TESTNAME'] = self.name
         env['HOME'] = _bytes2sys(self._testtmp)
+        if os.name == 'nt':
+            # py3.8+ ignores HOME: https://bugs.python.org/issue36264
+            env['USERPROFILE'] = env['HOME']
         formated_timeout = _bytes2sys(b"%d" % default_defaults['timeout'][1])
         env['HGTEST_TIMEOUT_DEFAULT'] = formated_timeout
         env['HGTEST_TIMEOUT'] = _bytes2sys(b"%d" % self._timeout)

tests/test-template-map.t

@@ -1972,6 +1972,7 b' if it is a relative path'
   > EOF
 
   $ HOME=`pwd`/home; export HOME
+  $ USERPROFILE=`pwd`/home; export USERPROFILE
 
   $ cat > latesttag/.hg/hgrc <<EOF
   > [ui]