Turning off “Display options” breaks node save

Problem

When "Display options" is unselected on the H5P configuration page, admin/config/system/h5p, saving an H5P node does not correctly store param data from H5P object.

Steps to reproduce

• Install a vanilla H5P instance, or verify "Display options" is checked in H5P config page (admin/config/system/h5p)
• Create a H5P node using Iframe Embedder (This is the object I tested with)
• Uncheck "Display options" on H5P config page (admin/config/system/h5p)
• Edit and save H5P node
• Node now displays "Page not found"
• Edit node and observe that Width, Min width, Height, and Source fields are empty
• Observe database values in h5p_nodes json_content and filtered fields are incorrect

Problem Cause

The _h5p_form_submit function is not attached to the H5P node edit form unless "Display options" is selected.

  // Display options
  if (variable_get('h5p_frame', TRUE)) {
    $form['h5p_options'] = array(
      // [...]
    );

    // Add display options
    // [...]

    $form['#submit'][] = '_h5p_form_submit';
  }

  return $form;

_h5p_form_submit() performs: $form_state['values']['json_content'] = json_encode($json_content->params);. Without this operation, the node json_content field is incorrectly stored and the filter field contains "{}".

Proposed resolution

Move $form['#submit'][] = '_h5p_form_submit'; outside the if statement.

Mitigation

Selecting "Display options" but not enabling any of the buttons produces give output similar or the same to disabling "Display options" and allows data to be saved correctly.