It just try to go through all pages of WPFA.
I do the following (I still use "rawcontinue=" for compatibility reasons):
https://fa.wikipedia.org/w/api.php?action=query&generator=allpages&gapfilterredir=nonredirects&gaplimit=max&colimit=max&prop=revisions|coordinates&gapnamespace=0&format=json&rawcontinue= https://fa.wikipedia.org/w/api.php?action=query&generator=allpages&gapfilterredir=nonredirects&gaplimit=max&colimit=max&prop=revisions|coordinates&gapnamespace=0&format=json&rawcontinue=&gapcontinue=.gd https://fa.wikipedia.org/w/api.php?action=query&generator=allpages&gapfilterredir=nonredirects&gaplimit=max&colimit=max&prop=revisions|coordinates&gapnamespace=0&format=json&rawcontinue=&gapcontinue=100000_(%D8%B9%D8%AF%D8%AF)
The problem is that the third request returns no entries at all, only:
{"query-continue":{"allpages":{"gapcontinue":"1289_(\u0645\u064a\u0644\u0627\u062f\u064a)"}},"limits":{"allpages":500,"coordinates":500}}... And it should return 500 entries like required, considering the fact that WPFA has many thousands of articles.
AFAIK, this was working fine (with WPFA) a few months ago and it seems to still work fine on many wikis (maybe a problem with certain charset?)