qa: Prepare functional tests for Windows

* Pass `sys.executable` when calling a python script via the subprocess
  module
* Don't remove the log file while it is still open and written to
* Properly use os.pathsep and os.path.sep when modifying the PATH
  environment variable
* util-tests: Use os.path.join for Windows compatibility

test/functional/test_framework/test_framework.py

@@ -99,7 +99,9 @@ class BitcoinTestFramework():
 
         PortSeed.n = self.options.port_seed
 
-        os.environ['PATH'] = self.options.srcdir + ":" + self.options.srcdir + "/qt:" + os.environ['PATH']
+        os.environ['PATH'] = self.options.srcdir + os.pathsep + \
+                             self.options.srcdir + os.path.sep + "qt" + os.pathsep + \
+                             os.environ['PATH']
 
         check_json_precision()
 
@@ -148,10 +150,11 @@ class BitcoinTestFramework():
             self.log.info("Note: bitcoinds were not stopped and may still be running")
 
         if not self.options.nocleanup and not self.options.noshutdown and success != TestStatus.FAILED:
-            self.log.info("Cleaning up")
-            shutil.rmtree(self.options.tmpdir)
+            self.log.info("Cleaning up {} on exit".format(self.options.tmpdir))
+            cleanup_tree_on_exit = True
         else:
             self.log.warning("Not cleaning up dir %s" % self.options.tmpdir)
+            cleanup_tree_on_exit = False
 
         if success == TestStatus.PASSED:
             self.log.info("Tests successful")
@@ -164,6 +167,8 @@ class BitcoinTestFramework():
             self.log.error("Hint: Call {} '{}' to consolidate all logs".format(os.path.normpath(os.path.dirname(os.path.realpath(__file__)) + "/../combine_logs.py"), self.options.tmpdir))
             exit_code = TEST_EXIT_FAILED
         logging.shutdown()
+        if cleanup_tree_on_exit:
+            shutil.rmtree(self.options.tmpdir)
         sys.exit(exit_code)
 
     # Methods to override in subclass test scripts.

test/functional/test_runner.py

@@ -268,7 +268,7 @@ def main():
     if args.help:
         # Print help for test_runner.py, then print help of the first script (with args removed) and exit.
         parser.print_help()
-        subprocess.check_call([(config["environment"]["SRCDIR"] + '/test/functional/' + test_list[0].split()[0])] + ['-h'])
+        subprocess.check_call([sys.executable, os.path.join(config["environment"]["SRCDIR"], 'test', 'functional', test_list[0].split()[0]), '-h'])
         sys.exit(0)
 
     check_script_list(config["environment"]["SRCDIR"])
@@ -312,7 +312,7 @@ def run_tests(test_list, src_dir, build_dir, exeext, tmpdir, jobs=1, enable_cove
     if len(test_list) > 1 and jobs > 1:
         # Populate cache
         try:
-            subprocess.check_output([tests_dir + 'create_cache.py'] + flags + ["--tmpdir=%s/cache" % tmpdir])
+            subprocess.check_output([sys.executable, tests_dir + 'create_cache.py'] + flags + ["--tmpdir=%s/cache" % tmpdir])
         except subprocess.CalledProcessError as e:
             sys.stdout.buffer.write(e.output)
             raise
@@ -342,7 +342,7 @@ def run_tests(test_list, src_dir, build_dir, exeext, tmpdir, jobs=1, enable_cove
                 print('\n============')
                 print('{}Combined log for {}:{}'.format(BOLD[1], testdir, BOLD[0]))
                 print('============\n')
-                combined_logs, _ = subprocess.Popen([os.path.join(tests_dir, 'combine_logs.py'), '-c', testdir], universal_newlines=True, stdout=subprocess.PIPE).communicate()
+                combined_logs, _ = subprocess.Popen([sys.executble, os.path.join(tests_dir, 'combine_logs.py'), '-c', testdir], universal_newlines=True, stdout=subprocess.PIPE).communicate()
                 print("\n".join(deque(combined_logs.splitlines(), combined_logs_len)))
 
     print_results(test_results, max_len_name, (int(time.time() - time0)))
@@ -412,7 +412,7 @@ class TestHandler:
             tmpdir_arg = ["--tmpdir={}".format(testdir)]
             self.jobs.append((t,
                               time.time(),
-                              subprocess.Popen([self.tests_dir + test_argv[0]] + test_argv[1:] + self.flags + portseed_arg + tmpdir_arg,
+                              subprocess.Popen([sys.executable, self.tests_dir + test_argv[0]] + test_argv[1:] + self.flags + portseed_arg + tmpdir_arg,
                                                universal_newlines=True,
                                                stdout=log_stdout,
                                                stderr=log_stderr),

test/util/bitcoin-util-test.py

@@ -44,7 +44,7 @@ def main():
     # Add the format/level to the logger
     logging.basicConfig(format=formatter, level=level)
 
-    bctester(os.path.join(env_conf["SRCDIR"], "test/util/data"), "bitcoin-util-test.json", env_conf)
+    bctester(os.path.join(env_conf["SRCDIR"], "test", "util", "data"), "bitcoin-util-test.json", env_conf)
 
 def bctester(testDir, input_basename, buildenv):
     """ Loads and parses the input file, runs all tests and reports results"""