dist/vue.runtime.esm.js
function getStyle (vnode, checkChild) {
  var res = {};
  var styleData;

  if (checkChild) {
    var childNode = vnode;
    while (childNode.componentInstance) {
      childNode = childNode.componentInstance._vnode;
      if (
        childNode && childNode.data &&
        (styleData = normalizeStyleData(childNode.data))
      ) {
        extend(res, styleData);
      }
    }
  }

  if ((styleData = normalizeStyleData(vnode.data))) {
    extend(res, styleData);
  }

  var parentNode = vnode;
  while ((parentNode = parentNode.parent)) {
    if (parentNode.data && (styleData = normalizeStyleData(parentNode.data))) {
      extend(res, styleData);
    }
  }
  return res
}
function getStyle (vnode, checkChild) {
  var res = {};
  var styleData;

  if (checkChild) {
    var childNode = vnode;
    while (childNode.componentInstance) {
      childNode = childNode.componentInstance._vnode;
      if (
        childNode && childNode.data &&
        (styleData = normalizeStyleData(childNode.data))
      ) {
        extend(res, styleData);
      }
    }
  }

  if ((styleData = normalizeStyleData(vnode.data))) {
    extend(res, styleData);
  }

  var parentNode = vnode;
  while ((parentNode = parentNode.parent)) {
    if (parentNode.data && (styleData = normalizeStyleData(parentNode.data))) {
      extend(res, styleData);
    }
  }
  return res
}
function getStyle ( vnode , checkChild ) { var res = { } ; var styleData ; if ( checkChild ) { var childNode = vnode ; while ( childNode . componentInstance ) { childNode = childNode . componentInstance . _vnode ; if ( childNode && childNode . data && ( styleData = normalizeStyleData ( childNode . data ) ) ) { extend ( res , styleData ) ; } } } if ( ( styleData = normalizeStyleData ( vnode . data ) ) ) { extend ( res , styleData ) ; } var parentNode = vnode ; while ( ( parentNode = parentNode . parent ) ) { if ( parentNode . data && ( styleData = normalizeStyleData ( parentNode . data ) ) ) { extend ( res , styleData ) ; } } return res }
parent component style should be after child's
so that parent component's style could override it
parent component style should be after child s so that parent component s style could override it