Wordpress woocommerce handling from address bar ( ?attr-)?

Question

WordPress

Tell me, in which file woocommerce processes the attr variable from the address bar -
the fact is that they brought attributes in Russian attr-weight, attr-length, etc., there is a third-party plugin that generates such links from the filter. The plugin itself is not tied to Russian names, it works by ID.
There was such a bug, if you create a filter and then go to page 2, for example site.ru/shop/page/2?attr-weight[]=1,
then WP throws an error 500.
If you replace the Russian letters site.ru/shop/page in the link /2?attr-123[]=1 the error disappears. At first they thought a third-party plugin makes such a mistake, by disabling it, the error remained.
Another such moment is why we think on woocommerce, if we make a link like site.ru/shop/page/2?attr1-weight[]=1
those. change the attr- variable itself to attr1-, the error disappears and a 404 falls out.
the question is where in woocommerce is the processing of this variable from the address bar ?attr-

Answer 1

Try looking through the files for the string "$_GET[attr-" (and "$_POST[attr-" just in case). Perhaps you will find someone who processes your attr
In general, it is desirable to get rid of non-English characters in slugs.