Issues updating post markup (e.g. when editing)

[palant]

The issue from #2216 and #2889 shows up in other circumstances as well. One scenario is post editing:

• Compose a post with the text “Hi there”.
• Click “Home” and reload to make this post show up.
• Edit the post text into “Hi #there” and save.

You will see a post showing “#there” instead of the expected “Hi #there”, reloading the page makes the post display correctly. The underlying issue here is again Vue being unable to update markup correctly: it tries to update HTML nodes, but it won’t add/remove nodes.