A few more Windows fixes.

backends.py

@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os, stat, re, pickle
+import os, sys, stat, re, pickle
 import interpreter, nodes
 import environment
 from meson_install import InstallData
@@ -295,7 +295,7 @@ class NinjaBackend(Backend):
         elem = NinjaBuildElement('install', 'CUSTOM_COMMAND', '')
         elem.add_dep('all')
         elem.add_item('DESC', 'Installing files.')
-        elem.add_item('COMMAND', [install_script, install_data_file])
+        elem.add_item('COMMAND', [sys.executable, install_script, install_data_file])
         elem.write(outfile)
         
         self.generate_target_install(d)
@@ -359,7 +359,7 @@ class NinjaBackend(Backend):
         test_script = os.path.join(script_root, 'meson_test.py')
         test_data = os.path.join(self.environment.get_scratch_dir(), 'meson_test_setup.dat')
         elem = NinjaBuildElement('test', 'CUSTOM_COMMAND', '')
-        elem.add_item('COMMAND', [test_script, test_data])
+        elem.add_item('COMMAND', [sys.executable, test_script, test_data])
         elem.add_item('DESC', 'Running test suite.')
         elem.write(outfile)
         

meson.py

@@ -30,7 +30,12 @@ build_types = ['plain', 'debug', 'optimized']
 buildtype_help = 'build type, one of: %s' % ', '.join(build_types)
 buildtype_help += ' (default: %default)'
 
-parser.add_option('--prefix', default='/usr/local', dest='prefix',
+if environment.is_windows():
+    def_prefix = 'c:/'
+else:
+    def_prefix = '/usr/local'
+
+parser.add_option('--prefix', default=def_prefix, dest='prefix',
                   help='the installation prefix (default: %default)')
 parser.add_option('--libdir', default='lib', dest='libdir',
                   help='the installation subdir of libraries (default: %default)')
@@ -55,7 +60,7 @@ class MesonApp():
 
     def __init__(self, dir1, dir2, script_file, options):
         (self.source_dir, self.build_dir) = self.validate_dirs(dir1, dir2)
-        if options.prefix[0] != '/':
+        if not os.path.isabs(options.prefix):
             raise RuntimeError('--prefix must be an absolute path.')
         self.meson_script_file = script_file
         self.options = options