Fix bug in deflate_stored() for zero-length input.
diff --git a/deflate.c b/deflate.c
index f13af8f..7817530 100644
--- a/deflate.c
+++ b/deflate.c
@@ -1040,7 +1040,6 @@
}
}
}
- Assert(strm->avail_out > 0, "bug2");
if (flush != Z_FINISH) return Z_OK;
if (s->wrap <= 0) return Z_STREAM_END;
@@ -1653,17 +1652,19 @@
* possible. If flushing, copy the remaining available input to next_out as
* stored blocks, if there is enough space.
*/
- unsigned len, left, have, last;
+ unsigned len, left, have, last = 0;
unsigned used = s->strm->avail_in;
- for (;;) {
+ do {
/* Set len to the maximum size block that we can copy directly with the
* available input data and output space. Set left to how much of that
* would be copied from what's left in the window.
*/
len = MAX_STORED; /* maximum deflate stored block length */
have = (s->bi_valid + 42) >> 3; /* number of header bytes */
+ if (s->strm->avail_out < have) /* need room for header */
+ break;
/* maximum stored block length that will fit in avail_out: */
- have = s->strm->avail_out > have ? s->strm->avail_out - have : 0;
+ have = s->strm->avail_out - have;
left = s->strstart - s->block_start; /* bytes left in window */
if (len > (ulg)left + s->strm->avail_in)
len = left + s->strm->avail_in; /* limit len to the input */
@@ -1677,7 +1678,8 @@
* copying to the window and the pending buffer instead. Also don't
* write an empty block when flushing -- deflate() does that.
*/
- if (len < min_block && (len == 0 || flush == Z_NO_FLUSH ||
+ if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
+ flush == Z_NO_FLUSH ||
len - left != s->strm->avail_in))
break;
@@ -1721,7 +1723,7 @@
s->strm->avail_out -= len;
s->strm->total_out += len;
}
- }
+ } while (last == 0);
/* Update the sliding window with the last s->w_size bytes of the copied
* data, or append all of the copied data to the existing window if less
@@ -1754,13 +1756,14 @@
s->insert += MIN(used, s->w_size - s->insert);
}
- /* If flushing or finishing and all input has been consumed, then done. If
- * the code above couldn't write a complete block to next_out, then the
- * code following this won't be able to either.
- */
- if (flush != Z_NO_FLUSH && s->strm->avail_in == 0 &&
- (long)s->strstart == s->block_start)
- return flush == Z_FINISH ? finish_done : block_done;
+ /* If the last block was written to next_out, then done. */
+ if (last)
+ return finish_done;
+
+ /* If flushing and all input has been consumed, then done. */
+ if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
+ s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
+ return block_done;
/* Fill the window with any remaining input. */
have = s->window_size - s->strstart - 1;
@@ -1791,20 +1794,18 @@
min_block = MIN(have, s->w_size);
left = s->strstart - s->block_start;
if (left >= min_block ||
- (left && flush != Z_NO_FLUSH && s->strm->avail_in == 0 &&
- left <= have)) {
+ ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
+ s->strm->avail_in == 0 && left <= have)) {
len = MIN(left, have);
last = flush == Z_FINISH && s->strm->avail_in == 0 &&
len == left ? 1 : 0;
_tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
s->block_start += len;
flush_pending(s->strm);
- if (last)
- return finish_started;
}
/* We've done all we can with the available input and output. */
- return need_more;
+ return last ? finish_started : need_more;
}
/* ===========================================================================
