Confirmation redirects URLs to internal URLs stopped being relative

I added a pull request and a new patch for this issue.

The last submitted patch, 6: 3319148-5.patch, failed testing. View results →

Added a new patch that also adapts the unit tests with the new logic.

Added the correct patch now.

-    // Check confirmation URL using absolute path.
+    $base_url = getenv('SIMPLETEST_BASE_URL');
+    if ($base_url) {
+      putenv('SIMPLETEST_BASE_URL=' . $base_url . '/base-path');
+    }
+
+   // Check confirmation URL using leading "/" internal path.
     $webform_confirmation_url
-      ->setSetting('confirmation_url', '/some-absolute-path')
+      ->setSetting('confirmation_url', '/some-internal-path')
       ->save();
     $this->postSubmission($webform_confirmation_url);
-    $assert_session->addressEquals('/some-absolute-path');
+    $assert_session->addressEquals('/some-internal-path');

That's a regression when /base-path is used. It must be $assert_session->addressEquals('/base-path/some-internal-path');

I will not touch this code unless something is broken in the webform module. If we make any more changes to the confirmation redirect URLs it will likely cause a regression for someone.