Opera: resizable TEXTAREAs don't show inside collapsible fieldsets

When a fieldset is collapsed by default, and when I click to open it, I don't see any TEXTAREA within which has the 'resizable' class.

This problem is probably specific to Opera (I'm using Opera 9.22, and 9.20), as I don't see it on Firefox/IE/Safari.

This problem is new to Drupal 6.x. It doesn't exist in Drupal 5.x.

I'm attaching a screenshot that demonstrates the problem. Notice the 'Log message' TEXTAREA which isn't shown.

Further info:

When I remove the following 5 lines from 'textarea.js', the problem is solved:

    // Inherit visibility
    if ($(this).is(':hidden')) {
      $(this).parent().hide();
      $(this).show();
    }

(But then the nifty teaser TEXTAREA on the node editing form won't work correctly.)

The fix:

I believe Opera does the right thing. The above code effectively does textarea_wrapper.style.display = 'none' on the enclosing element, so why should opening the fieldset cancel this operation?

To fix this problem I changed:

    if ($(this).is(':hidden')) {

To:

    if ($(this).is(':hidden') && $(grippie).is(':visible')) {

This ensures that the TEXTAREA wrapper is hidden because the TEXAREA was explicitly hidden and not because it is a descendant of some hidden element.

(I'll soon attach the patch.)