Panels template files: Inheriting a tpl file in a sub theme

Question

In my Drupal custom parent theme, I have included a file called panels-pane.tpl.php. This is the main panel pane template. By including this tpl file in my theme, I can override the one in the Panels module folder, which allows me to control its mark-up.

It all works fine. However, when I enable a sub theme that is based on the parent theme, this particular file is ignored. All the other files are inherited.

How can I get this file to be inherited as well?

Would it be possible to force this to be always loaded regardless of the theme?

Please note: I am talking about overriding the panels-pane.tpl.php that comes from the original Panels module. I am not talking about creating a custom Panels layout.

Steps I have tried:

1. Copying the panels-pane.tpl.php into the sub themes template directory.
2. Clearing the caches
3. Uninstalling and then re-enable the parent and sub themes

UPDATED Panels has a file called panels.module. In it has a function called panels_theme(), which contains the following:

  $theme['panels_pane'] = array(
    'variables' => array('output' => array(), 'pane' => array(), 'display' => array()),
    'path' => drupal_get_path('module', 'panels') . '/templates',
    'template' => 'panels-pane',
  );

Can I use this to control panels-pane.tpl.php from inside a module by using theme_registry_alter?

I have tried the following code, but it doesn't work:

function legendary_theme_registry_alter(&$theme_registry) {
 $theme['panels_pane'] = array(
    'variables' => array('output' => array(), 'pane' => array(), 'display' => array()),
    'path' => drupal_get_path('theme', 'legendary') . '/templates',
    'template' => 'panels-pane',
  );
}

Answer 1

Here's the weird news, just having a panels-pane.tpl.php in a parent theme should work. It's working for me in a highly used parent theme. So I'm guessing any theme suggestions or other steps aren't going to cut it...

I would check for typos, in this case I would look at the file name (sounds like that's fine), then I would check the sub-theme info file to make sure that's set correctly (although it sounds like that may also be right)

base theme = base_theme_name

Then I would check file permissions on tpl/theme folder. 664 tends to work for me, and apache needs access to it and the folder it's in.

If that seems fine my two steps before I panic with drupal are:

drush rr

restart apache

Hope that helps.