path_redirect incompatibility with themekey

In some cases (I found this on panel nodes specifically) the code in path_redirect_init() ends up initializing the theme, which ends up breaking themekey and stopping it from being able to switch theme properly. I found this out using the deg snippet that is discussed in the issue liked to below (see this comment http://drupal.org/node/754970#comment-4966192 for a snippet that actually works). This shows that just after path_redirect_init is run, the theme is initialized to the default theme. Commenting out path_redirect_goto() in path_redirect_init fixes the issue and gets themekey going again, but obviously breaks path_redirect.

See #754970: Skipped rule checking because another module already initialized the theme engine for more details.

After shoving a load of debug statements in the code of path_redirect_goto(), I found that the problem actually lies in this snippet of code:

    if (url($redirect['redirect']) == url($_GET['q'])) {
      // Prevent infinite loop redirection.
      watchdog('path_redirect', 'Redirect to <code>%redirect

is causing an infinite loop; redirect cancelled.', array('%redirect' => $redirect['redirect_url']), WATCHDOG_WARNING, l(t('Edit'), 'admin/build/path-redirect/edit/'. $redirect['rid']));
}

Commenting out that watchdog statement solves the problem. I find it hard to see how a call to watchdog would cause this, but there you go. We are using the core syslog module as opposed to dblog, if that makes any difference!