theme_get_settings() incorrectly changes returned value based on current user

If you look closely at the function definition of theme_get_settings(), you’ll see a not-so-obvious bug.

theme_get_settings() should be returning the values for these settings as they are stored in the database (or as the defaults define them). However, you’ll notice that the returned value for toggle_search setting is altered depending on the user that is currently viewing the site. That's just wrong!

The check for !module_exists('search') || !user_access('search content') should be placed where the setting is being used in the business logic; in this case that check should be inside template_preprocess_page because that's where the theme's search box is being added to the page.tpl.php.

If a theme is trying to do something based on the actual value of toggle_search, the theme will often (but not always) get the wrong value returned by theme_get_settings().

For example, because of this bug, the Zen theme and any theme following the “Initializing the default values” section of the Advanced Theme Settings documentation, will encounter a bizarre error where the search box will get disabled at random times. See #311458: Search box gets disabled after arbitrary amount of time

FYI, the search box feature of themes has been removed from D7, so this is not an issue for D7.