+
+ /* Guard against corrupt/malicious frames that set EOP and
+ a backdated granpos; don't rewind more samples than we
+ actually have */
+ if(extra > (v->pcm_current - v->pcm_returned)<<hs)
+ extra = (v->pcm_current - v->pcm_returned)<<hs;
+
+ /* we use ogg_int64_t for granule positions because a
+ uint64 isn't universally available. Unfortunately,
+ that means granposes can be 'negative' and result in
+ extra being negative */
+ if(extra<0)
+ extra=0;
+