Single file component: conditional templates malfunctionning after 2.1.0

Hi,

Not sure which Vue subproject this issue refers to, but conditional templates started to malfunction in single file component since 2.1.0.

Simple reproduction:

<template>
  <div>
    <template v-if="true === true">
      <section class="section">
        <div class="container">
          Should be shown
        </div>
      </section>
    </template>
    <template v-else>
      <p>Shoud not be shown</p>
    </template>
  </div>
</template>

Should not be shown is shown, whereas Should be shown should be.

Note if you remove the outer div class container and leave only the inner text, Should be shown is indeed shown.

This only happen with single file component (e.g. this jsfiddle works).

EDIT: Fix wrong jsfiddle link

[bartlomieju]

Can confirm, I have exactly same issue since update to 2.1.0 yesterday. It also happens with v-show

[yyx990803]

Closing in favor of #4290 since both seem to be the same issue