FIX Preview link when no locale set

[emteknetnz]

Issue silverstripe/.github#272

Fixes vendor/silverstripe/cms/tests/behat/features/preview-a-page.feature:12 - which breaks when silverstripe/recipe-kitchen-sink is run including silverstripe/cms behat tests.

The issue that behat is running into is that the preview link will not show anything as no locale has been defined in a behat context

[GuySartorelli]

This is starting to feel really flaky.

I've done a root cause analysis and this PR is what causes the problem that results in needing this "temp locale" in the first place.

This fixes it without needing a temp locale:

     public function updatePreviewLink(&$link): void
     {
         $owner = $this->owner;
-        $info = $owner->LocaleInformation(FluentState::singleton()->getLocale());
+        $locale = FluentState::singleton()->getLocale();
+        if ($locale === null || $locale === '') {
+            return;
+        }
+        $info = $owner->LocaleInformation($locale);

         if (!$info->getSourceLocale()) {
             $link = null;
         }
     }

With this change, if there is no current locale (i.e. locales haven't been set up yet) it won't update the preview URL. It'll only update it when there is a current locale (i.e. locales have been set up).

[emteknetnz]

Updated

[GuySartorelli]

Should also revert the changes that were made in 2714bff and b14687a - the temporary locale isn't needed anymore.

[emteknetnz]

Surprisingly yes, looks like the previous CI failure was actually just from rendering the preview link from a template.

Reverted as second commit, so do not squash merge

[GuySartorelli]

LGTM