TYPO3 Core

My take on this issue:

The first plugin on a page with a redirect wins. The request can be terminated immediately to save useless processing of other plugins.

Edge-cases discussed in various places, like having plugins that need to be called for persisting data, is IMO an invalid use case and bad software design. You don't want a single request to handle multiple application logic steps at once, where one thing relies upon the other.

The issue only occurs if the action is a cached action.

Patch set 1 for branch TYPO3_8-7 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58581

Patch set 1 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58582

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58582

Helmut Hummel wrote:

but then the HTML gets cached while response->setStatus() and response->setHeader() do not

What is a use case for caching a plugin action that does a redirect?

I have an extension with a showAction() that returns a detail view of a database record. I was trying to show a specific “this record could not be found” page with a 404 – instead of the regular 404 page of the website. This is important mostly for records that have been recently deleted but might still be linked somewhere or returned by search engines. I tried to achieve this by forwarding to a specific showNotFoundAction() (see below). Which means the forwarding is being called by an action that has to be cached (the showAction).

I am happy to hear about different solutions for that particular problem. Nevertheless, redirectToUri() is a provided method and the resulting forwarding should in my opinion never be done via an HTML meta tag. And even if it is, there is still the bug of printing the full HTML page into the content part of the template (see snippet in the original post).

    public function showAction(\My\Extension\Domain\Model\MyModel $record = null)
    {
        if (!is_null($record)) {
            $this->view->assign('data', $record);
        } else {
            $uri = $this->uriBuilder
                ->setTargetPageUid($GLOBALS['TSFE']->id)
                ->setArguments(['tx_myextension_plugin'=>['action'=>'showNotFound']])
                ->buildFrontendUri();
            $this->redirectToUri($uri, 0, 404);
        }
    }