+ /* If offset is too large for return type, report error instead of wrong
+ offset value. Buffers may not be larger than INT_MAX so the casts are
+ safe.
+ */
+ /* FIXME: This calculation *underflows* when offset smaller than pre-read */
+ if ( ( stream->pos.offset - ( (int)stream->bufend + (int)stream->ungetidx ) ) > ( LONG_MAX - stream->bufidx ) )
+ {
+ /* integer overflow */
+ _PDCLIB_errno = _PDCLIB_ERANGE;
+ return -1;
+ }
+ return (long int)( stream->pos.offset - ( ( (int)stream->bufend - (int)stream->bufidx ) + stream->ungetidx ) );