"You have specified an invalid media URL or embed code." - Form and Node display on same page breaks "provided services "

Okay, I ran into this edge case the other day and thought i would document it.

If you have an complex page, say using panels and you are simultaneously displaying an embedded video in one pane and have a node add form in a different pane, the embedded media field thinks that the only allowable content provider is that of the displayed video.

I found the answer in the code. When emfield_system_list is called, it stores the list of providers in a static variable. If that list is then called a second time in the same invocation (like I am doing with panels) then it grabs the original provider list instead of finding the correct providers.

function emfield_system_list($module, $provider = NULL, $load = TRUE) {
  // Maintain a static list of providers.
    static $files;
  

  if (!isset($files)) {
    // Initialize our static variable.
    $files = array();
  }
  if (!isset($files[$module])) {
    // Initialize the file listing for the invoking module.
    $files[$module] = array();
  }

My solution was to comment out the 'static $files', but of course this will cause all subsequent calls to emfield_system_list to run over the disk looking for provider plugins. Anyhow, hope this saves somebody some hair.