Requirement error because drupal_utf8mb4_test table was not dropped

yes, issues are looking fixed now

Thanks all for working on this!

Testing core gate now has an exception, specifying when tests are not needed, see: https://www.drupal.org/about/core/policies/core-change-policies/core-gat... → . One of the conditions is that

"The issue has clear ‘Steps to reproduce’ in the Issue Summary."

.

So my question is - beside the manual table creation - do we know a way how we can achieve that the table is created, exception is thrown only afterwards and therefore the table is not deleted correctly? What other exceptions can be thrown after the table is created and before it is dropped? If there are some possibilities, then great. If not, should not we consider an alternative approach to check and drop the table in the catch block instead?

I have looked at all CREATE TABLE statements in D7 core and none of these is using IF NOT EXISTS.

What this issue reports is that the current code returns FALSE even when the test table already exists, which would be understood as the utf8mb4 support is not available.

  try {
    $this->query("CREATE TABLE {drupal_utf8mb4_test} (id VARCHAR(255), PRIMARY KEY(id(255))) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci ROW_FORMAT=DYNAMIC ENGINE=INNODB");
  } catch (Exception $e) {
    return FALSE;
  }

I cannot say that what described happens very often. I can see that another CMS, to check the utf8mb4 support, first deletes the test table if it exists, then it tries to create it, and deletes it once done the test. The equivalent Drupal code would be similar to the following one.

// Ensure that the MySQL server supports large prefixes and utf8mb4.
  try {
    $this->query("DROP TABLE IF EXISTS {drupal_utf8mb4_test}");
    $this->query("CREATE TABLE {drupal_utf8mb4_test} (id VARCHAR(255), PRIMARY KEY(id(255))) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci ROW_FORMAT=DYNAMIC ENGINE=INNODB");
  }
  catch (Exception $e) {
    return FALSE;
  }
  $this->query("DROP TABLE IF EXISTS {drupal_utf8mb4_test}");
  return TRUE;
}

I checked what Drupal 10.x does, but I did not find any code which verifies utf8mb4 is supported. (I guess Drupal 10 requires a MySQL version which surely supports utf8mb4.)