pm-enable and pm-disable not working for themes

In environment_6.inc in function drush_get_themes, the call to system_theme_data seems to be what causes the enable/disable theme to revert. Inspection of DB before the call shows the new value and after the call shows the old value.

That is why this worked prior to merging into pm-enable as the old implementation didn't have the system_theme_data call.

call order:
pm-enable/disable (pm.drush.inc)
drush_get_projects (update_6.inc)
drush_get_themes (environment_6.inc)
system_theme_data() (drupal core's system.module)

The values set in the DB are correct up through the initial part of the system_theme_data function.

There is a call to system_get_file_database. On return from that, the database still has the correct information in it. However, the $themes array that was returned does not. system_theme_data then deletes the theme information from the system table and inserts the information from the $themes array.

That is how this is being overwritten.

I am not sure what system_get_files_database is supposed to do, but I am not sure if the logic is correct.

750  function system_get_files_database(&$files, $type) {
751    // Extract current files from database.
752    $result = db_query("SELECT filename, name, type, status, throttle, schema_version FROM {system} WHERE type = '%s'", $type);
753    while ($file = db_fetch_object($result)) {
754      if (isset($files[$file->name]) && is_object($files[$file->name])) {
755        $file->old_filename = $file->filename;
756        foreach ($file as $key => $value) {
757          if (!isset($files[$file->name]) || !isset($files[$file->name]->$key)) {
758            $files[$file->name]->$key = $value;
759          }
760        }
761      }
762    }
763  }

The question I have is regarding line 757. To begin with first condition is always going to be false as you passed the condition in 754. What 754 is saying is that if you don't have an array item with that file name or if you don't have that key in the array, then you set the key.

In our scenario, pm_enable/disable theme, we come through system_get_files_database twice (via calls to drush_get_projects), first when it gets the initial list and then afterwards when they get the list in preparation for giving the final status. The problem arises in that in the second call, the key is already in the list. With the check on line 757, as the status key exists, it does not write it. However, it contains the old value. In this case at least, it would need to update the status key.

At this point, I am hitting system module functionality. I don't know if it should skip the existing keys or update them. If the system module is wrong, then we can have it fixed so that pm-enable/disable theme would work. If not, we need to figure out what to do instead of that second call to drush_get_projects.

If system.module is correct, then we need to set status differently. We can't set it directly in the db as it will just be overwritten. I think the answer would be to set it in the list of 'files'/themes that is returned by system_theme_data().

If that approach is acceptable, then I have a proposed patch for the Drupal 6.x environment. The patch is to the environment_6.inc file.

Created an issue against core: http://drupal.org/node/759766 (call to system_get_files_database via system_theme_data overwrites changes made directly to database).