message: refactor: reduce if-else nesting, coalesce conditions
diff: @@ -86,8 +86,7 @@ export function renderMixin (Vue: Class<Component>) {
  // return error render result,
  // or previous vnode to prevent render error causing blank component
  /* istanbul ignore else */
  - if (process.env.NODE_ENV !== 'production') {
  - if (vm.$options.renderError) {
  + if (process.env.NODE_ENV !== 'production' && vm.$options.renderError) {
  try {
  vnode = vm.$options.renderError.call(vm._renderProxy, vm.$createElement, e)
  } catch (e) {
  @@ -97,9 +96,6 @@ export function renderMixin (Vue: Class<Component>) {
  } else {
  vnode = vm._vnode
  }
  - } else {
  - vnode = vm._vnode
  - }
  }
  // return empty vnode in case the render function errored out
  if (!(vnode instanceof VNode)) {
  