1.3.1 performance degradation for :has() + :first in a selector

1.3.1 performance degradation for :has() + :first in a selector


I'm sure this is not the most elegant line of code, but in 1.2.6,
there was no performance hit (i.e. a moderately complex page/form
loaded in the blink of an eye). In 1.3.1 this now takes > 10 seconds
with 100% cpu:
var parentWithIdAttribute = jQuery(this).parents('fieldset:has
([id]):first').attr('id');
This is used to determine the context of a bunch of labels and legends
within a selector.each().
Commenting out this single line restores the performance (but
obviously breaks my app).
Not sure whether I should raise this as a bug...?