Unable to delete a tempstore when a non ASCII character is used.

Problem/Motivation

When attempting to delete a tempstore with a non ASCII character such as en or em dash the following error is thrown.

Drupal\Core\Database\DatabaseExceptionWrapper: SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (ascii_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '=': DELETE FROM {key_value_expire} WHERE ("name" IN (:db_condition_placeholder_0)) AND ("collection" = :db_condition_placeholder_1); Array ( [:db_condition_placeholder_0] => 2020—2021 [:db_condition_placeholder_1] => tempstore.shared.my_module_name ) in Drupal\Core\KeyValueStore\StorageBase->delete() (line 52 of core/lib/Drupal/Core/KeyValueStore/StorageBase.php).

Steps to reproduce

Create a custom module then attempt the following:

$keyword = '2020–2021';
$tempstore = \Drupal::service('tempstore.shared')->get('my_module_name');
$tempstore->delete($keyword);

Proposed resolution

Update the way tables are created to allow for the collation specified in settings.php before defaulting to ascii.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet