Outputting markup from custom text field is not possible

Fixes the issue for me. Does this warrant a test?

@mbaynton It has the "Needs tests" issue tag and I would say that the need is warranted (to help prevent regressions)

+++ b/core/modules/views/src/Plugin/views/field/Custom.php
@@ -63,7 +65,7 @@ public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    */
...
-    return $this->options['alter']['text'];
+    return Markup::create(Xss::filterAdmin($this->options['alter']['text']));

This should likely use ViewsRenderPipelineMarkup as it's in the pipeline so we can find these later when/if we find a better solution.

Well it is rendering so it would be nice if it was a value object... but there is precedent to it like this with a ['#markup' => 'render array']

A couple of examples that use #markup already.
\Drupal\views\Plugin\views\field\Dropbutton
\Drupal\views\Plugin\views\field\LinkBase

If the tests fail, blame Lauri:P

This was the approach I was thinking of from the start. It marks the ViewsRenderPipelineness for later review.

Thanks for tagging this for rc target triage! To have committers consider it for inclusion in RC, we should add a statement to the issue summary of why we need to make this change during RC, including what happens if we do not make the change and what any disruptions from it are. We can add a section <h3>Why this should be an RC target</h3> to the summary.

Evaluated the issue for RC eligibility, felt it should be :D.

Made changes @xjm noted above to issue summary

I tested the patch manually and confirmed the issue is resolved by the patch. Added screenshots to the issue summary.

Added a retest for php5.5_mysql5.5

I don't think this is rc eligible, but it should definitely be a candidate for rc target because it is a bug fix and not a coding standard, doc update, testing improvement or library update as written in https://www.drupal.org/core/d8-allowed-changes#rc.

Agreed. One-line bug fix (+tests), fixing a regression that was introduced just before RC. Moving to RC Target and asking for forgiveness. ;)

Committed and pushed to 8.0.x. Thanks!

Hi, I've just discovered that even inline CSS styling is stripped from the global custom text field inside views. Is it a desidered behaviour?

Ok, thanks :-)