chash cache doesn't take take root page into account

[stephanschuler]

Summary

The internal chash cache (database table tx_realurl_chashcache) maps a given combination of query string and query parameters to a single chash value. It's intended to not recalculate chashe values when resolving GETvars from SEO URLs but to just look them up.

This can conflicts when common non-page records should be displayed on different detail pages on different root pages that share the same language and by accident the same page path to the detail page.

Example

Given a page tree like this:

• first-domain [1]
  • new-details [2]
• second-domain [3]
  • news-details [4]

Given a news record "testnews" with News-ID 10.

The news record is to be shared across both root pages.

There are two URLs to the same news record:

Encoded URL	Decoded URL
https://first-domain/news-details/testnews	index.php?id=2&news=10&chash=foo
https://second-domain/news-details/testnews	index.php=id=4&news=10&chash=bar

Expected

The database table tx_realurl_chashcache should look like this:

spurl_hash	chash_string	spurl_string
aaaaa	foo	first-domain/news-details/testnews
bbbbb	bar	second-domain/news-details/testnews

Actual behavior

The database table tx_realurl_chashcache looks like this:

spurl_hash	chash_string	spurl_string
bbbbb	bar	news-details/testnews

Solution

There's the \Tx\Realurl\Hooks\UrlRewritingHook::$additionalParametersForChash.

This can be used to add the current hostname to the chash cache.