windows: make uv_fs_stat use open + fstat to support long paths

src/win/fs.c

@@ -491,14 +491,36 @@ void fs__readdir(uv_fs_t* req, const wchar_t* path, int flags) {
 
 void fs__stat(uv_fs_t* req, const wchar_t* path) {
   int result;
+  unsigned short mode;
 
-  result = _wstati64(path, &req->stat);
+  fs__open(req, path, _O_RDONLY, 0);
+  if (req->result == -1) {
+    return;
+  }
+
+  result = _fstati64(req->result, &req->stat);
   if (result == -1) {
     req->ptr = NULL;
   } else {
+
+    /* 
+     * VC CRT doesn't properly set S_IFDIR in _fstati64,
+     * so we set it here if path is a directory.
+     */
+    if (GetFileAttributesW(path) & FILE_ATTRIBUTE_DIRECTORY) {
+      mode = req->stat.st_mode;
+      mode &= ~_S_IFMT;
+      mode |= _S_IFDIR;
+      
+      req->stat.st_mode = mode;
+      assert((req->stat.st_mode & _S_IFMT) == _S_IFDIR);
+    }
+
     req->ptr = &req->stat;
   }
 
+  _close(req->result);
+
   SET_REQ_RESULT(req, result);
 }