Content from redirector pages appears in search results but isn't editable in the CMS

[madmatt]

Scenario:

1. Create a standard page, add some content into $Content, save and publish. Content is indexed into Elastic - this is fine.
2. Change the page type to RedirectorPage. Content is now hidden in the CMS (as the Content field is hidden) but content is not removed from Elastic as it still exists on SiteTree.

This only happens with the $Content field if it's indexed, because that field is on SiteTree, not a sub-class that gets changed.

It's probably enough to treat this as a special case, rather than doing anything more complicated, and just block the indexing of the Content field if the source_class is RedirectorPage.

[madmatt]

Worth noting this would also affect any fields on the pages where the page type is changed between two pages that have slightly different hierarchy but a common ancestor.

For example, if you have SiteTree -> Page -> LandingPage and SiteTree -> Page -> OtherPage and on OtherPage you hide a bunch of fields from either SiteTree or Page, then those fields may still end up being indexed. I don't know of a good way around that beyond forcing users to decide for every single page type what fields should be indexed.

[n8-dev]

For anyone still stumbling across this, a current adhoc solution is to create a RedirectorPageExtension
With the following code.

    public function onBeforeWrite()
    {
        if ($this->getOwner()->ShowInSearch) {
            $this->getOwner()->ShowInSearch = 0;
        }
    }

Since this is a core Silverstripe page type, perhaps this solution could be added to this repo