vs2010: fix target_to_build_root method

Python's os.path.split() does not split the path into its components.
Instead, split the path with str.split() using the OS's file system
separator.

mesonbuild/backend/vs2010backend.py

@@ -217,10 +217,8 @@ class Vs2010Backend(backends.Backend):
         if target.subdir == '':
             return ''
 
-        directories = os.path.split(target.subdir)
-        directories = list(filter(bool,directories)) #Filter out empty strings
-
-        return '/'.join(['..']*len(directories))
+        directories = target.subdir.split(os.sep)
+        return os.sep.join(['..']*len(directories))
 
     def special_quote(self, arr):
         return ['"%s"' % i for i in arr]

test cases/common/106 subproject subdir/meson.build

@@ -0,0 +1,6 @@
+project('proj', 'c')
+subproject('sub')
+libSub = dependency('sub', fallback: ['sub', 'libSub'])
+
+exe = executable('prog', 'prog.c', dependencies: libSub)
+test('subproject subdir', exe)

test cases/common/106 subproject subdir/prog.c

@@ -0,0 +1,5 @@
+#include <sub.h>
+
+int main() {
+	return sub();
+}

test cases/common/106 subproject subdir/subprojects/sub/lib/meson.build

@@ -0,0 +1,2 @@
+lib = static_library('sub', 'sub.c')
+libSub = declare_dependency(include_directories: include_directories('.'), link_with: lib)

test cases/common/106 subproject subdir/subprojects/sub/lib/sub.c

@@ -0,0 +1,5 @@
+#include "sub.h"
+
+int sub() {
+	return 0;
+}

test cases/common/106 subproject subdir/subprojects/sub/lib/sub.h

@@ -0,0 +1,6 @@
+#ifndef SUB_H
+#define SUB_H
+
+int sub();
+
+#endif

test cases/common/106 subproject subdir/subprojects/sub/meson.build

@@ -0,0 +1,2 @@
+project('sub', 'c')
+subdir('lib')