There is a bug in function pdf_stm_flush() in file pdf-stm.c at line 327.
It is produced when beckend is full or not all cache is written to beckend.
327: cache_size = stm->cache->wp - stm->cache->rp;
328: written_bytes = pdf_stm_be_write (stm->backend,
stm->cache->data + stm->cache->rp,
cache_size);
332: /* Rewind the cache */
pdf_buffer_rewind (stm->cache);
In line 332 stream cache is erased, so cache_size-written_bytes is lost.
