Issue with post frontmatter and pagination

[thoemmi]

I have some problems when using post's frontmatter and paginating. Additional properties I define in the a post's frontmatter are not available when I use pagination.

E.g. I have this post:

---
layout: default
title: 'Some post'
customfield: 'bar'

---
## Hello World!

And my index.html look like this

---
layout: default
paginate: 1
title: 'A different title'

---
{% for post in paginator.posts %}
  {{ post.title }}-{{ post.customfield }}
{% endfor %}

Then the first page is rendered with

  Some post-

but I expect

  Some post-bar

I'm always confused by Pretzel's code: on the one hand PageContext has several properties, and on the other hand it has a Bag, where some of the properties are duplicated.

This PR contains "only" a unit test to reproduce the issue. I don't know how to fix it at the moment.

[laedit]

Thanks a lot for the reporting 😃 I know that the paginator is kind of "weird" at best, but I hadn't take the time to investigate it. Seems the time has come!

[laedit]

So finally it is not linked to the paginatordirectly but by the way we populate the liquid's template data in LiquidEngine: the paginator is passed directly without processing the data of each of his posts.

So right now the customfield is accessible through post.bag["customfield"]. An evolution could be to pass the paginator in LiquidEngine.CreatePageData but to call a ToHash method, like the one used on ContextDrop, which will return a Hash of all properties of paginator and call ToHash on each Page.

About PageContext, I think it is because Razor is also supported: it doesn't use page.customfield but @Model.Bag["customfield"] to access to custom values in page. So the properties are needed to facilitate the access to usual values.