Fix stat when subdirectory is a file

Make sure that stat on Windows, both with and without cache, returns
"missing file" when running stat on notadir/foo where notadir is a
file.

Author: Fredrik Medley

src/disk_interface.cc

@@ -105,7 +105,8 @@ bool StatAllFilesInDir(const string& dir, map<string, TimeStamp>* stamps,
 
   if (find_handle == INVALID_HANDLE_VALUE) {
     DWORD win_err = GetLastError();
-    if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND)
+    if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND ||
+        win_err == ERROR_DIRECTORY)  // File and not a directory
       return true;
     *err = "FindFirstFileExA(" + dir + "): " + GetLastErrorString();
     return false;

src/disk_interface_test.cc

@@ -63,6 +63,27 @@ TEST_F(DiskInterfaceTest, StatMissingFile) {
   EXPECT_EQ("", err);
 }
 
+#ifdef _WIN32
+TEST_F(DiskInterfaceTest, StatMissingFileWithCache) {
+  string err;
+  disk_.AllowStatCache(true);
+
+  EXPECT_EQ(0, disk_.Stat("nosuchfile", &err));
+  EXPECT_EQ("", err);
+
+  // On Windows, the errno for a file in a nonexistent directory
+  // is different.
+  EXPECT_EQ(0, disk_.Stat("nosuchdir/nosuchfile", &err));
+  EXPECT_EQ("", err);
+
+  // On POSIX systems, the errno is different if a component of the
+  // path prefix is not a directory.
+  ASSERT_TRUE(Touch("notadir"));
+  EXPECT_EQ(0, disk_.Stat("notadir/nosuchfile", &err));
+  EXPECT_EQ("", err);
+}
+#endif
+
 TEST_F(DiskInterfaceTest, StatBadPath) {
   string err;
 #ifdef _WIN32