From a437cd1955186060a8c5768fef739830d2711d0c Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Sun, 15 Oct 2017 21:38:35 +0300
Subject: [PATCH 1/7] Add command to run Python scripts with the current
 interpreter.

---
 mesonbuild/mesonmain.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index 8d5fb8563..049132222 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -303,6 +303,12 @@ def run(args, mainfile=None):
             return mconf.run(remaining_args)
         elif cmd_name == 'wrap':
             return wraptool.run(remaining_args)
+        elif cmd_name == 'runpython':
+            import runpy
+            script_file = remaining_args[0]
+            sys.argv[1:] = remaining_args[1:]
+            runpy.run_path(script_file, run_name='__main__')
+            sys.exit(0)
 
     # No special command? Do the basic setup/reconf.
     if len(args) >= 2 and args[0] == '--internal':

From 9d67e5030b6c86ce33f43ae7a5b827f299d68a3e Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Sun, 15 Oct 2017 21:48:03 +0300
Subject: [PATCH 2/7] Changed code to use detected executables rather than
 hardcoding sys.executable.

---
 mesonbuild/mesonlib.py        | 9 +++++++++
 mesonbuild/modules/python3.py | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/mesonbuild/mesonlib.py b/mesonbuild/mesonlib.py
index f74c6c17b..35aa03667 100644
--- a/mesonbuild/mesonlib.py
+++ b/mesonbuild/mesonlib.py
@@ -22,6 +22,15 @@ import collections
 
 from glob import glob
 
+if sys.executable.endswith('meson.exe'):
+    # In Windows and using the MSI installed executable.
+    meson_command = [sys.executable]
+    python_command = [sys.executable, 'runpython']
+else:
+    meson_command = [sys.executable, os.path.join(os.path.split(__file__)[0], '..', 'meson.py')]
+    python_command = [sys.executable]
+
+
 # Put this in objects that should not get dumped to pickle files
 # by accident.
 import threading
diff --git a/mesonbuild/modules/python3.py b/mesonbuild/modules/python3.py
index 4fae88b47..989e839a9 100644
--- a/mesonbuild/modules/python3.py
+++ b/mesonbuild/modules/python3.py
@@ -52,7 +52,7 @@ class Python3Module(ExtensionModule):
 
     @noKwargs
     def find_python(self, state, args, kwargs):
-        py3 = dependencies.ExternalProgram('python3', sys.executable, silent=True)
+        py3 = dependencies.ExternalProgram('python3', mesonlib.python_command, silent=True)
         return ModuleReturnValue(py3, [py3])
 
     @noKwargs

From b3dfb80c15cae24c66d07425bb7a327528438a55 Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Thu, 9 Nov 2017 00:59:06 +0200
Subject: [PATCH 3/7] Tests can be run with an external Meson command.

---
 run_project_tests.py |  6 +++---
 run_tests.py         | 20 ++++++++++++++++++--
 run_unittests.py     |  9 +++++----
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/run_project_tests.py b/run_project_tests.py
index 17e095b7a..d3da4e6c8 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -33,7 +33,7 @@ import time
 import multiprocessing
 import concurrent.futures as conc
 import re
-from run_unittests import get_fake_options, run_configure_inprocess
+from run_unittests import get_fake_options, run_configure
 
 from run_tests import get_backend_commands, get_backend_args_for_dir, Backend
 from run_tests import ensure_backend_detects_changes
@@ -327,9 +327,9 @@ def _run_test(testdir, test_build_dir, install_dir, extra_args, compiler, backen
     test_args = parse_test_args(testdir)
     gen_start = time.time()
     # Configure in-process
-    gen_command = [meson_command, '--prefix', '/usr', '--libdir', 'lib', testdir, test_build_dir]\
+    gen_args = ['--prefix', '/usr', '--libdir', 'lib', testdir, test_build_dir]\
         + flags + test_args + extra_args
-    (returncode, stdo, stde) = run_configure_inprocess(gen_command)
+    (returncode, stdo, stde) = run_configure(meson_command, gen_args)
     try:
         logfile = os.path.join(test_build_dir, 'meson-logs/meson-log.txt')
         with open(logfile, errors='ignore') as f:
diff --git a/run_tests.py b/run_tests.py
index 79c963948..4ac458cdd 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -31,6 +31,12 @@ from glob import glob
 
 Backend = Enum('Backend', 'ninja vs xcode')
 
+if 'MESON_EXE' in os.environ:
+    import shlex
+    meson_exe = shlex.split(os.environ['MESON_EXE'])
+else:
+    meson_exe = None
+
 if mesonlib.is_windows() or mesonlib.is_cygwin():
     exe_suffix = '.exe'
 else:
@@ -127,18 +133,28 @@ def get_fake_options(prefix):
 def should_run_linux_cross_tests():
     return shutil.which('arm-linux-gnueabihf-gcc-7') and not platform.machine().lower().startswith('arm')
 
-def run_configure_inprocess(commandlist):
+def run_configure_inprocess(meson_command, commandlist):
     old_stdout = sys.stdout
     sys.stdout = mystdout = StringIO()
     old_stderr = sys.stderr
     sys.stderr = mystderr = StringIO()
     try:
-        returncode = mesonmain.run(commandlist[1:], commandlist[0])
+        returncode = mesonmain.run(commandlist, meson_command)
     finally:
         sys.stdout = old_stdout
         sys.stderr = old_stderr
     return returncode, mystdout.getvalue(), mystderr.getvalue()
 
+def run_configure_external(full_command):
+    pc, o, e = mesonlib.Popen_safe(full_command)
+    return pc.returncode, o, e
+
+def run_configure(meson_command, commandlist):
+    global meson_exe
+    if meson_exe:
+        return run_configure_external(meson_exe + commandlist)
+    return run_configure_inprocess(meson_command, commandlist)
+
 class FakeEnvironment(object):
     def __init__(self):
         self.cross_info = None
diff --git a/run_unittests.py b/run_unittests.py
index 80c58ea0c..2d4dfbbe5 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -40,7 +40,7 @@ from mesonbuild.dependencies import PkgConfigDependency, ExternalProgram
 
 from run_tests import exe_suffix, get_fake_options, FakeEnvironment
 from run_tests import get_builddir_target_args, get_backend_commands, Backend
-from run_tests import ensure_backend_detects_changes, run_configure_inprocess
+from run_tests import ensure_backend_detects_changes, run_configure
 from run_tests import should_run_linux_cross_tests
 
 
@@ -460,8 +460,9 @@ class BasePlatformTests(unittest.TestCase):
         # Get the backend
         # FIXME: Extract this from argv?
         self.backend = getattr(Backend, os.environ.get('MESON_UNIT_TEST_BACKEND', 'ninja'))
-        self.meson_args = [os.path.join(src_root, 'meson.py'), '--backend=' + self.backend.name]
-        self.meson_command = [sys.executable] + self.meson_args
+        self.meson_mainfile = os.path.join(src_root, 'meson.py')
+        self.meson_args = ['--backend=' + self.backend.name]
+        self.meson_command = [sys.executable, self.meson_mainfile] + self.meson_args
         self.mconf_command = [sys.executable, os.path.join(src_root, 'meson.py'), 'configure']
         self.mintro_command = [sys.executable, os.path.join(src_root, 'meson.py'), 'introspect']
         self.mtest_command = [sys.executable, os.path.join(src_root, 'meson.py'), 'test', '-C', self.builddir]
@@ -527,7 +528,7 @@ class BasePlatformTests(unittest.TestCase):
         self.privatedir = os.path.join(self.builddir, 'meson-private')
         if inprocess:
             try:
-                out = run_configure_inprocess(self.meson_args + args + extra_args)[1]
+                out = run_configure(self.meson_mainfile, self.meson_args + args + extra_args)[1]
             except:
                 self._print_meson_log()
                 raise

From 5d51bc79c7555e681a0c638da9528458257744ae Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Sat, 11 Nov 2017 01:53:23 +0200
Subject: [PATCH 4/7] Replaced sys.executable use with the mesonlib equivalent.

---
 mesonbuild/backend/ninjabackend.py  |  4 ++--
 mesonbuild/backend/vs2010backend.py |  9 +++++----
 mesonbuild/backend/xcodebackend.py  |  2 +-
 mesonbuild/dependencies/base.py     |  2 +-
 mesonbuild/environment.py           | 12 ++++--------
 mesonbuild/mesonmain.py             |  2 +-
 mesonbuild/scripts/regen_checker.py | 14 +++++---------
 msi/createmsi.py                    |  5 ++---
 run_project_tests.py                |  2 +-
 run_tests.py                        |  7 ++++---
 run_unittests.py                    | 19 ++++++++++---------
 11 files changed, 36 insertions(+), 42 deletions(-)

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index c633daf76..cea1b0832 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -2524,7 +2524,7 @@ rule FORTRAN_DEP_HACK
         gcno_elem = NinjaBuildElement(self.all_outputs, 'meson-clean-gcno', 'CUSTOM_COMMAND', 'PHONY')
         script_root = self.environment.get_script_dir()
         clean_script = os.path.join(script_root, 'delwithsuffix.py')
-        gcno_elem.add_item('COMMAND', [sys.executable, clean_script, '.', 'gcno'])
+        gcno_elem.add_item('COMMAND', mesonlib.python_command + [clean_script, '.', 'gcno'])
         gcno_elem.add_item('description', 'Deleting gcno files.')
         gcno_elem.write(outfile)
         # Alias that runs the target defined above
@@ -2533,7 +2533,7 @@ rule FORTRAN_DEP_HACK
         gcda_elem = NinjaBuildElement(self.all_outputs, 'meson-clean-gcda', 'CUSTOM_COMMAND', 'PHONY')
         script_root = self.environment.get_script_dir()
         clean_script = os.path.join(script_root, 'delwithsuffix.py')
-        gcda_elem.add_item('COMMAND', [sys.executable, clean_script, '.', 'gcda'])
+        gcda_elem.add_item('COMMAND', mesonlib.python_command + [clean_script, '.', 'gcda'])
         gcda_elem.add_item('description', 'Deleting gcda files.')
         gcda_elem.write(outfile)
         # Alias that runs the target defined above
diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index e4e969690..efa432990 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -396,10 +396,11 @@ class Vs2010Backend(backends.Backend):
         action = ET.SubElement(root, 'ItemDefinitionGroup')
         customstep = ET.SubElement(action, 'PostBuildEvent')
         cmd_raw = [target.command] + target.args
-        cmd = [sys.executable, os.path.join(self.environment.get_script_dir(), 'commandrunner.py'),
-               self.environment.get_build_dir(),
-               self.environment.get_source_dir(),
-               self.get_target_dir(target)] + self.environment.get_build_command()
+        cmd = mesonlib.python_command +
+            [os.path.join(self.environment.get_script_dir(), 'commandrunner.py'),
+             self.environment.get_build_dir(),
+             self.environment.get_source_dir(),
+             self.get_target_dir(target)] + self.environment.get_build_command()
         for i in cmd_raw:
             if isinstance(i, build.BuildTarget):
                 cmd.append(os.path.join(self.environment.get_build_dir(), self.get_target_filename(i)))
diff --git a/mesonbuild/backend/xcodebackend.py b/mesonbuild/backend/xcodebackend.py
index 199d7df11..ea9be308b 100644
--- a/mesonbuild/backend/xcodebackend.py
+++ b/mesonbuild/backend/xcodebackend.py
@@ -567,7 +567,7 @@ class XCodeBackend(backends.Backend):
         self.write_line('shellPath = /bin/sh;')
         script_root = self.environment.get_script_dir()
         test_script = os.path.join(script_root, 'meson_test.py')
-        cmd = [sys.executable, test_script, test_data, '--wd', self.environment.get_build_dir()]
+        cmd = mesonlib.python_command[test_script, test_data, '--wd', self.environment.get_build_dir()]
         cmdstr = ' '.join(["'%s'" % i for i in cmd])
         self.write_line('shellScript = "%s";' % cmdstr)
         self.write_line('showEnvVarsInLog = 0;')
diff --git a/mesonbuild/dependencies/base.py b/mesonbuild/dependencies/base.py
index fcc74b538..15b47bc35 100644
--- a/mesonbuild/dependencies/base.py
+++ b/mesonbuild/dependencies/base.py
@@ -434,7 +434,7 @@ class ExternalProgram:
                         commands = commands[1:]
                     # Windows does not ship python3.exe, but we know the path to it
                     if len(commands) > 0 and commands[0] == 'python3':
-                        commands[0] = sys.executable
+                        commands = mesonlib.python_command + commands[1:]
                 return commands + [script]
         except Exception:
             pass
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index d9146eba3..90450074b 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -325,14 +325,10 @@ class Environment:
         return self.coredata
 
     def get_build_command(self, unbuffered=False):
-        # If running an executable created with cx_freeze,
-        # Python might not be installed so don't prefix
-        # the command with it.
-        if sys.executable.endswith('meson.exe'):
-            return [sys.executable]
-        if unbuffered:
-            [sys.executable, '-u', self.meson_script_launcher]
-        return [sys.executable, self.meson_script_launcher]
+        cmd = mesonlib.meson_command[:]
+        if unbuffered and 'python' in cmd[0]:
+            cmd = [cmd[0],'-u'] + cmd[1:]
+        return cmd
 
     def is_header(self, fname):
         return is_header(fname)
diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index 049132222..342e98fa1 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -155,7 +155,7 @@ class MesonApp:
 
     def _generate(self, env):
         mlog.debug('Build started at', datetime.datetime.now().isoformat())
-        mlog.debug('Python binary:', sys.executable)
+        mlog.debug('Main binary:', sys.executable)
         mlog.debug('Python system:', platform.system())
         mlog.log(mlog.bold('The Meson build system'))
         self.check_pkgconfig_envvar(env)
diff --git a/mesonbuild/scripts/regen_checker.py b/mesonbuild/scripts/regen_checker.py
index 53c5428f7..e8fbd1963 100644
--- a/mesonbuild/scripts/regen_checker.py
+++ b/mesonbuild/scripts/regen_checker.py
@@ -32,15 +32,11 @@ def need_regen(regeninfo, regen_timestamp):
     return False
 
 def regen(regeninfo, mesonscript, backend):
-    if sys.executable.lower().endswith('meson.exe'):
-        cmd_exe = [sys.executable]
-    else:
-        cmd_exe = [sys.executable, mesonscript]
-    cmd = cmd_exe + ['--internal',
-           'regenerate',
-           regeninfo.build_dir,
-           regeninfo.source_dir,
-           '--backend=' + backend]
+    cmd = mesonlib.meson_command + ['--internal',
+                                    'regenerate',
+                                    regeninfo.build_dir,
+                                    regeninfo.source_dir,
+                                    '--backend=' + backend]
     subprocess.check_call(cmd)
 
 def run(args):
diff --git a/msi/createmsi.py b/msi/createmsi.py
index 7f165d88a..4f1fd5bab 100755
--- a/msi/createmsi.py
+++ b/msi/createmsi.py
@@ -17,6 +17,7 @@
 import sys, os, subprocess, shutil, uuid
 from glob import glob
 import platform
+import shutil
 import xml.etree.ElementTree as ET
 
 sys.path.append(os.getcwd())
@@ -82,9 +83,7 @@ class PackageGenerator:
         modules = [os.path.splitext(os.path.split(x)[1])[0] for x in glob(os.path.join('mesonbuild/modules/*'))]
         modules = ['mesonbuild.modules.' + x for x in modules if not x.startswith('_')]
         modulestr = ','.join(modules)
-        python = 'c:\\Python\python.exe'
-        if sys.executable:
-            python = sys.executable
+        python = shutil.which('python')
         cxfreeze = os.path.join(os.path.dirname(python), "Scripts", "cxfreeze")
         if not os.path.isfile(cxfreeze):
             print("ERROR: This script requires cx_freeze module")
diff --git a/run_project_tests.py b/run_project_tests.py
index d3da4e6c8..27caabd76 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -603,7 +603,7 @@ def check_meson_commands_work():
     testdir = 'test cases/common/1 trivial'
     with AutoDeletedDir(tempfile.mkdtemp(prefix='b ', dir='.')) as build_dir:
         print('Checking that configuring works...')
-        gen_cmd = [sys.executable, meson_command, testdir, build_dir] + backend_flags
+        gen_cmd = mesonlib.meson_command + [testdir, build_dir] + backend_flags
         pc, o, e = Popen_safe(gen_cmd)
         if pc.returncode != 0:
             raise RuntimeError('Failed to configure {!r}:\n{}\n{}'.format(testdir, e, o))
diff --git a/run_tests.py b/run_tests.py
index 4ac458cdd..b287a1a47 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -223,11 +223,12 @@ if __name__ == '__main__':
                         'coverage.process_startup()\n')
             env['COVERAGE_PROCESS_START'] = '.coveragerc'
             env['PYTHONPATH'] = os.pathsep.join([td] + env.get('PYTHONPATH', []))
-        returncode += subprocess.call([sys.executable, 'run_unittests.py', '-v'], env=env)
+        returncode += subprocess.call(mesonlib.python_command + ['run_unittests.py', '-v'], env=env)
         # Ubuntu packages do not have a binary without -6 suffix.
         if should_run_linux_cross_tests():
             print(mlog.bold('Running cross compilation tests.').get_text(mlog.colorize_console))
             print()
-            returncode += subprocess.call([sys.executable, 'run_cross_test.py', 'cross/ubuntu-armhf.txt'], env=env)
-        returncode += subprocess.call([sys.executable, 'run_project_tests.py'] + sys.argv[1:], env=env)
+            returncode += subprocess.call(mesonlib.python_command + ['run_cross_test.py', 'cross/ubuntu-armhf.txt'],
+                                          env=env)
+        returncode += subprocess.call(mesonlib.python_command + ['run_project_tests.py'] + sys.argv[1:], env=env)
     sys.exit(returncode)
diff --git a/run_unittests.py b/run_unittests.py
index 2d4dfbbe5..cdf29024e 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -34,6 +34,7 @@ import mesonbuild.mesonlib
 import mesonbuild.coredata
 from mesonbuild.interpreter import ObjectHolder
 from mesonbuild.mesonlib import is_linux, is_windows, is_osx, is_cygwin, windows_proof_rmtree
+from mesonbuild.mesonlib import python_command, meson_command
 from mesonbuild.environment import Environment
 from mesonbuild.dependencies import DependencyException
 from mesonbuild.dependencies import PkgConfigDependency, ExternalProgram
@@ -462,10 +463,10 @@ class BasePlatformTests(unittest.TestCase):
         self.backend = getattr(Backend, os.environ.get('MESON_UNIT_TEST_BACKEND', 'ninja'))
         self.meson_mainfile = os.path.join(src_root, 'meson.py')
         self.meson_args = ['--backend=' + self.backend.name]
-        self.meson_command = [sys.executable, self.meson_mainfile] + self.meson_args
-        self.mconf_command = [sys.executable, os.path.join(src_root, 'meson.py'), 'configure']
-        self.mintro_command = [sys.executable, os.path.join(src_root, 'meson.py'), 'introspect']
-        self.mtest_command = [sys.executable, os.path.join(src_root, 'meson.py'), 'test', '-C', self.builddir]
+        self.meson_command = meson_command + self.meson_args
+        self.mconf_command = meson_command + ['configure']
+        self.mintro_command = meson_command + ['introspect']
+        self.mtest_command = meson_command + ['test', '-C', self.builddir]
         # Backend-specific build commands
         self.build_command, self.clean_command, self.test_command, self.install_command, \
             self.uninstall_command = get_backend_commands(self.backend)
@@ -1122,14 +1123,14 @@ class AllPlatformTests(BasePlatformTests):
             # exelist + some argument. This is meant to test that setting
             # something like `ccache gcc -pipe` or `distcc ccache gcc` works.
             wrapper = os.path.join(testdir, 'compiler wrapper.py')
-            wrappercc = [sys.executable, wrapper] + cc.get_exelist() + ['-DSOME_ARG']
+            wrappercc = python_command + [wrapper] + cc.get_exelist() + ['-DSOME_ARG']
             wrappercc_s = ''
             for w in wrappercc:
                 wrappercc_s += shlex.quote(w) + ' '
             os.environ[evar] = wrappercc_s
             wcc = getattr(env, 'detect_{}_compiler'.format(lang))(False)
             # Check static linker too
-            wrapperlinker = [sys.executable, wrapper] + linker.get_exelist() + linker.get_always_args()
+            wrapperlinker = python_command + [wrapper] + linker.get_exelist() + linker.get_always_args()
             wrapperlinker_s = ''
             for w in wrapperlinker:
                 wrapperlinker_s += shlex.quote(w) + ' '
@@ -1718,12 +1719,12 @@ class WindowsTests(BasePlatformTests):
         os.environ['PATH'] += os.pathsep + testdir
         prog = ExternalProgram('test-script-ext')
         self.assertTrue(prog.found(), msg='test-script-ext not found in PATH')
-        self.assertPathEqual(prog.get_command()[0], sys.executable)
+        self.assertPathEqual(prog.get_command()[0], python_command[0])
         self.assertPathBasenameEqual(prog.get_path(), 'test-script-ext.py')
         # Finding a script in PATH with extension works and adds the interpreter
         prog = ExternalProgram('test-script-ext.py')
         self.assertTrue(prog.found(), msg='test-script-ext.py not found in PATH')
-        self.assertPathEqual(prog.get_command()[0], sys.executable)
+        self.assertPathEqual(prog.get_command()[0], python_command[0])
         self.assertPathBasenameEqual(prog.get_path(), 'test-script-ext.py')
 
     def test_ignore_libs(self):
@@ -2247,7 +2248,7 @@ class RewriterTests(unittest.TestCase):
         super().setUp()
         src_root = os.path.dirname(__file__)
         self.testroot = os.path.realpath(tempfile.mkdtemp())
-        self.rewrite_command = [sys.executable, os.path.join(src_root, 'mesonrewriter.py')]
+        self.rewrite_command = python_command + [os.path.join(src_root, 'mesonrewriter.py')]
         self.tmpdir = os.path.realpath(tempfile.mkdtemp())
         self.workdir = os.path.join(self.tmpdir, 'foo')
         self.test_dir = os.path.join(src_root, 'test cases/rewrite')

From 105ea1e597a6ec5e711d95ec6339597ef759c475 Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Mon, 20 Nov 2017 22:15:08 +0200
Subject: [PATCH 5/7] Make the full test suite runnable with an external
 command.

---
 mesonbuild/mesonmain.py | 86 +++++++++++++++++++++--------------------
 run_project_tests.py    | 21 +++++++++-
 run_unittests.py        |  5 ++-
 3 files changed, 67 insertions(+), 45 deletions(-)

diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index 342e98fa1..fa8c9e376 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -23,12 +23,9 @@ from . import mlog, coredata
 from .mesonlib import MesonException
 from .wrap import WrapMode, wraptool
 
-
-parser = argparse.ArgumentParser(prog='meson')
-
 default_warning = '1'
 
-def add_builtin_argument(name, **kwargs):
+def add_builtin_argument(p, name, **kwargs):
     k = kwargs.get('dest', name.replace('-', '_'))
     c = coredata.get_builtin_option_choices(k)
     b = True if kwargs.get('action', None) in ['store_true', 'store_false'] else False
@@ -42,31 +39,45 @@ def add_builtin_argument(name, **kwargs):
         kwargs['default'] = default
     else:
         kwargs['default'] = argparse.SUPPRESS
-    parser.add_argument('--' + name, help=h, **kwargs)
+    p.add_argument('--' + name, help=h, **kwargs)
 
-add_builtin_argument('prefix')
-add_builtin_argument('libdir')
-add_builtin_argument('libexecdir')
-add_builtin_argument('bindir')
-add_builtin_argument('sbindir')
-add_builtin_argument('includedir')
-add_builtin_argument('datadir')
-add_builtin_argument('mandir')
-add_builtin_argument('infodir')
-add_builtin_argument('localedir')
-add_builtin_argument('sysconfdir')
-add_builtin_argument('localstatedir')
-add_builtin_argument('sharedstatedir')
-add_builtin_argument('backend')
-add_builtin_argument('buildtype')
-add_builtin_argument('strip', action='store_true')
-add_builtin_argument('unity')
-add_builtin_argument('werror', action='store_true')
-add_builtin_argument('layout')
-add_builtin_argument('default-library')
-add_builtin_argument('warnlevel', dest='warning_level')
-add_builtin_argument('stdsplit', action='store_false')
-add_builtin_argument('errorlogs', action='store_false')
+def create_parser():
+    p = argparse.ArgumentParser(prog='meson')
+    add_builtin_argument(p, 'prefix')
+    add_builtin_argument(p, 'libdir')
+    add_builtin_argument(p, 'libexecdir')
+    add_builtin_argument(p, 'bindir')
+    add_builtin_argument(p, 'sbindir')
+    add_builtin_argument(p, 'includedir')
+    add_builtin_argument(p, 'datadir')
+    add_builtin_argument(p, 'mandir')
+    add_builtin_argument(p, 'infodir')
+    add_builtin_argument(p, 'localedir')
+    add_builtin_argument(p, 'sysconfdir')
+    add_builtin_argument(p, 'localstatedir')
+    add_builtin_argument(p, 'sharedstatedir')
+    add_builtin_argument(p, 'backend')
+    add_builtin_argument(p, 'buildtype')
+    add_builtin_argument(p, 'strip', action='store_true')
+    add_builtin_argument(p, 'unity')
+    add_builtin_argument(p, 'werror', action='store_true')
+    add_builtin_argument(p, 'layout')
+    add_builtin_argument(p, 'default-library')
+    add_builtin_argument(p, 'warnlevel', dest='warning_level')
+    add_builtin_argument(p, 'stdsplit', action='store_false')
+    add_builtin_argument(p, 'errorlogs', action='store_false')
+    p.add_argument('--cross-file', default=None,
+                   help='File describing cross compilation environment.')
+    p.add_argument('-D', action='append', dest='projectoptions', default=[], metavar="option",
+                   help='Set the value of an option, can be used several times to set multiple options.')
+    p.add_argument('-v', '--version', action='version',
+                   version=coredata.version)
+    # See the mesonlib.WrapMode enum for documentation
+    p.add_argument('--wrap-mode', default=WrapMode.default,
+                   type=wrapmodetype, choices=WrapMode,
+                   help='Special wrap mode to use')
+    p.add_argument('directories', nargs='*')
+    return p
 
 def wrapmodetype(string):
     try:
@@ -76,18 +87,6 @@ def wrapmodetype(string):
         msg = 'invalid argument {!r}, use one of {}'.format(string, msg)
         raise argparse.ArgumentTypeError(msg)
 
-parser.add_argument('--cross-file', default=None,
-                    help='File describing cross compilation environment.')
-parser.add_argument('-D', action='append', dest='projectoptions', default=[], metavar="option",
-                    help='Set the value of an option, can be used several times to set multiple options.')
-parser.add_argument('-v', '--version', action='version',
-                    version=coredata.version)
-# See the mesonlib.WrapMode enum for documentation
-parser.add_argument('--wrap-mode', default=WrapMode.default,
-                    type=wrapmodetype, choices=WrapMode,
-                    help='Special wrap mode to use')
-parser.add_argument('directories', nargs='*')
-
 class MesonApp:
 
     def __init__(self, dir1, dir2, script_launcher, handshake, options, original_cmd_line_args):
@@ -278,12 +277,13 @@ def run_script_command(args):
         raise MesonException('Unknown internal command {}.'.format(cmdname))
     return cmdfunc(cmdargs)
 
-def run(args, mainfile=None):
+def run(original_args, mainfile=None):
     if sys.version_info < (3, 4):
         print('Meson works correctly only with python 3.4+.')
         print('You have python %s.' % sys.version)
         print('Please update your environment')
         return 1
+    args = original_args[:]
     if len(args) > 0:
         # First check if we want to run a subcommand.
         cmd_name = args[0]
@@ -325,6 +325,8 @@ def run(args, mainfile=None):
     else:
         handshake = False
 
+    parser = create_parser()
+
     args = mesonlib.expand_arguments(args)
     options = parser.parse_args(args)
     args = options.directories
@@ -348,7 +350,7 @@ def run(args, mainfile=None):
     try:
         if mainfile is None:
             raise AssertionError('I iz broken. Sorry.')
-        app = MesonApp(dir1, dir2, mainfile, handshake, options, sys.argv)
+        app = MesonApp(dir1, dir2, mainfile, handshake, options, original_args)
     except Exception as e:
         # Log directory does not exist, so just print
         # to stdout.
diff --git a/run_project_tests.py b/run_project_tests.py
index 27caabd76..b94a976f2 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -322,13 +322,30 @@ def run_test(skipped, testdir, extra_args, compiler, backend, flags, commands, s
             finally:
                 mlog.shutdown() # Close the log file because otherwise Windows wets itself.
 
+def pass_prefix_to_test(dirname):
+    if '40 prefix' in dirname:
+        return False
+    return True
+
+def pass_libdir_to_test(dirname):
+    if '8 install' in dirname:
+        return False
+    if '39 libdir' in dirname:
+        return False
+    return True
+
 def _run_test(testdir, test_build_dir, install_dir, extra_args, compiler, backend, flags, commands, should_fail):
     compile_commands, clean_commands, install_commands, uninstall_commands = commands
     test_args = parse_test_args(testdir)
     gen_start = time.time()
     # Configure in-process
-    gen_args = ['--prefix', '/usr', '--libdir', 'lib', testdir, test_build_dir]\
-        + flags + test_args + extra_args
+    if pass_prefix_to_test(testdir):
+        gen_args = ['--prefix', '/usr']
+    else:
+        gen_args = []
+    if pass_libdir_to_test(testdir):
+        gen_args += ['--libdir', 'lib']
+    gen_args += [testdir, test_build_dir] + flags + test_args + extra_args
     (returncode, stdo, stde) = run_configure(meson_command, gen_args)
     try:
         logfile = os.path.join(test_build_dir, 'meson-logs/meson-log.txt')
diff --git a/run_unittests.py b/run_unittests.py
index cdf29024e..fe7507470 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -41,7 +41,7 @@ from mesonbuild.dependencies import PkgConfigDependency, ExternalProgram
 
 from run_tests import exe_suffix, get_fake_options, FakeEnvironment
 from run_tests import get_builddir_target_args, get_backend_commands, Backend
-from run_tests import ensure_backend_detects_changes, run_configure
+from run_tests import ensure_backend_detects_changes, run_configure, meson_exe
 from run_tests import should_run_linux_cross_tests
 
 
@@ -1588,6 +1588,9 @@ class FailureTests(BasePlatformTests):
         Assert that running meson configure on the specified @contents raises
         a error message matching regex @match.
         '''
+        if meson_exe is not None:
+            # Because the exception happens in a different process.
+            raise unittest.SkipTest('Can not test assert raise tests with an external Meson command.')
         if langs is None:
             langs = []
         with open(self.mbuild, 'w') as f:

From 22adda16179e11dd7e5ca34a34e6286afcf6c0c9 Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Mon, 20 Nov 2017 23:38:26 +0200
Subject: [PATCH 6/7] Review fixes.

---
 mesonbuild/backend/vs2010backend.py |  4 ++--
 mesonbuild/backend/xcodebackend.py  |  2 +-
 mesonbuild/environment.py           |  2 +-
 mesonbuild/mesonlib.py              |  4 ++--
 mesonbuild/scripts/regen_checker.py | 11 ++++++-----
 msi/createmsi.py                    |  1 -
 6 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index efa432990..69ee3e53a 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -23,7 +23,7 @@ from .. import dependencies
 from .. import mlog
 from .. import compilers
 from ..compilers import CompilerArgs
-from ..mesonlib import MesonException, File
+from ..mesonlib import MesonException, File, python_command
 from ..environment import Environment
 
 def autodetect_vs_version(build):
@@ -396,7 +396,7 @@ class Vs2010Backend(backends.Backend):
         action = ET.SubElement(root, 'ItemDefinitionGroup')
         customstep = ET.SubElement(action, 'PostBuildEvent')
         cmd_raw = [target.command] + target.args
-        cmd = mesonlib.python_command +
+        cmd = python_command + \
             [os.path.join(self.environment.get_script_dir(), 'commandrunner.py'),
              self.environment.get_build_dir(),
              self.environment.get_source_dir(),
diff --git a/mesonbuild/backend/xcodebackend.py b/mesonbuild/backend/xcodebackend.py
index ea9be308b..aca3aeae9 100644
--- a/mesonbuild/backend/xcodebackend.py
+++ b/mesonbuild/backend/xcodebackend.py
@@ -567,7 +567,7 @@ class XCodeBackend(backends.Backend):
         self.write_line('shellPath = /bin/sh;')
         script_root = self.environment.get_script_dir()
         test_script = os.path.join(script_root, 'meson_test.py')
-        cmd = mesonlib.python_command[test_script, test_data, '--wd', self.environment.get_build_dir()]
+        cmd = mesonlib.python_command + [test_script, test_data, '--wd', self.environment.get_build_dir()]
         cmdstr = ' '.join(["'%s'" % i for i in cmd])
         self.write_line('shellScript = "%s";' % cmdstr)
         self.write_line('showEnvVarsInLog = 0;')
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index 90450074b..58cc9b979 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -327,7 +327,7 @@ class Environment:
     def get_build_command(self, unbuffered=False):
         cmd = mesonlib.meson_command[:]
         if unbuffered and 'python' in cmd[0]:
-            cmd = [cmd[0],'-u'] + cmd[1:]
+            cmd.insert(1, '-u')
         return cmd
 
     def is_header(self, fname):
diff --git a/mesonbuild/mesonlib.py b/mesonbuild/mesonlib.py
index 35aa03667..83bfdbe29 100644
--- a/mesonbuild/mesonlib.py
+++ b/mesonbuild/mesonlib.py
@@ -22,12 +22,12 @@ import collections
 
 from glob import glob
 
-if sys.executable.endswith('meson.exe'):
+if os.path.basename(sys.executable) == 'meson.exe':
     # In Windows and using the MSI installed executable.
     meson_command = [sys.executable]
     python_command = [sys.executable, 'runpython']
 else:
-    meson_command = [sys.executable, os.path.join(os.path.split(__file__)[0], '..', 'meson.py')]
+    meson_command = [sys.executable, os.path.join(os.path.dirname(__file__), '..', 'meson.py')]
     python_command = [sys.executable]
 
 
diff --git a/mesonbuild/scripts/regen_checker.py b/mesonbuild/scripts/regen_checker.py
index e8fbd1963..a9b00c7b4 100644
--- a/mesonbuild/scripts/regen_checker.py
+++ b/mesonbuild/scripts/regen_checker.py
@@ -14,6 +14,7 @@
 
 import sys, os
 import pickle, subprocess
+from mesonbuild.mesonlib import meson_command
 
 # This could also be used for XCode.
 
@@ -32,11 +33,11 @@ def need_regen(regeninfo, regen_timestamp):
     return False
 
 def regen(regeninfo, mesonscript, backend):
-    cmd = mesonlib.meson_command + ['--internal',
-                                    'regenerate',
-                                    regeninfo.build_dir,
-                                    regeninfo.source_dir,
-                                    '--backend=' + backend]
+    cmd = meson_command + ['--internal',
+                           'regenerate',
+                           regeninfo.build_dir,
+                           regeninfo.source_dir,
+                           '--backend=' + backend]
     subprocess.check_call(cmd)
 
 def run(args):
diff --git a/msi/createmsi.py b/msi/createmsi.py
index 4f1fd5bab..3ea09587d 100755
--- a/msi/createmsi.py
+++ b/msi/createmsi.py
@@ -17,7 +17,6 @@
 import sys, os, subprocess, shutil, uuid
 from glob import glob
 import platform
-import shutil
 import xml.etree.ElementTree as ET
 
 sys.path.append(os.getcwd())

From f9e88cd37e6babc1de476398f54a540f3eeca1c7 Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Tue, 21 Nov 2017 00:26:24 +0200
Subject: [PATCH 7/7] Added release note mention of embedded Python in MSI
 packages.

---
 docs/markdown/snippets/builtin-python.md | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 docs/markdown/snippets/builtin-python.md

diff --git a/docs/markdown/snippets/builtin-python.md b/docs/markdown/snippets/builtin-python.md
new file mode 100644
index 000000000..01bb6e09c
--- /dev/null
+++ b/docs/markdown/snippets/builtin-python.md
@@ -0,0 +1,9 @@
+# Embedded Python in Windows MSI packages
+
+Meson now ships an internal version of Python in the MSI installer packages.
+This means that it can run Python scripts that are part of your build
+transparently. That is, if you do the following:
+
+    myprog = find_program('myscript.py')
+
+Then Meson will run the script with its internal Python version if necessary.