Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -10907,12 +10907,16 @@
             format("auto a = unique_ptr < Foo < Bar>[10]> ;", Spaces));
 }
 
-// Since this test case uses UNIX-style file path. We disable it for MS
-// compiler.
-#if !defined(_MSC_VER) && !defined(__MINGW32__)
-
 TEST(FormatStyle, GetStyleOfFile) {
   vfs::InMemoryFileSystem FS;
+
+  // Set CWD so that clang::vfs::FileSystem::makeAbsolute and
+  // llvm::sys::fs::make_absolute return the same thing.
+  llvm::SmallString<128> InitialDirectory;
+  std::error_code EC = llvm::sys::fs::current_path(InitialDirectory);
+  EXPECT_EQ(EC.value(), 0);
+  FS.setCurrentWorkingDirectory(InitialDirectory);
+
   // Test 1: format file in the same directory.
   ASSERT_TRUE(
       FS.addFile("/a/.clang-format", 0,
@@ -10938,8 +10942,6 @@
   ASSERT_EQ(Style3, getGoogleStyle());
 }
 
-#endif // _MSC_VER
-
 TEST_F(ReplacementTest, FormatCodeAfterReplacements) {
   // Column limit is 20.
   std::string Code = "Type *a =\n"