#1855: Addresses "TypeError: Cannot read property 'compile' of undefined"

[w0rd-driven]

This checks to make sure an object is returned from render.getRenderer(ext);.

The following snippet changes https://github.com/hexojs/hexo/blob/master/lib/theme/processors/view.js#L18 to be something like https://github.com/hexojs/hexo/blob/master/lib/theme/processors/source.js#L28-L35, but there may be cases it doesn't properly account for.

exports.pattern = new Pattern(function(path) {
  if (!_.startsWith(path, 'layout/')) return false;

  path = path.substring(7);
  var regex = /(^|\/)[\.]/;
  if (regex.test(path) || common.isTmpFile(path) || ~path.indexOf('node_modules')) return false;

  return {path: path};
});

[chrisl8888]

Seems simple enough.