lzx_compress.c: chosen_sequences[] length was 1 too short

[wimlib] / src / lzx_compress.c

diff --git a/src/lzx_compress.c b/src/lzx_compress.c
index 33943af7fa41d1e4d4cb3f4a66bdbc4acd27e93e..ec90ba1640cc0a11f18b1b848e5dfee28e915356 100644 (file)
--- a/src/lzx_compress.c
+++ b/src/lzx_compress.c
@@ -410,8 +410,10 @@ struct lzx_compressor {
 
        /* The matches and literals that the parser has chosen for the current
         * block.  The required length of this array is limited by the maximum
-        * number of matches that can ever be chosen for a single block.  */
-       struct lzx_sequence chosen_sequences[DIV_ROUND_UP(LZX_DIV_BLOCK_SIZE, LZX_MIN_MATCH_LEN)];
+        * number of matches that can ever be chosen for a single block, plus
+        * one for the special entry at the end.  */
+       struct lzx_sequence chosen_sequences[
+                      DIV_ROUND_UP(LZX_DIV_BLOCK_SIZE, LZX_MIN_MATCH_LEN) + 1];
 
        /* Tables for mapping adjusted offsets to offset slots  */
 
@@ -548,7 +550,7 @@ struct lzx_output_bitstream {
 
 /* Can the specified number of bits always be added to 'bitbuf' after any
  * pending 16-bit coding units have been flushed?  */
-#define CAN_BUFFER(n)  ((n) <= (8 * sizeof(machine_word_t)) - 16)
+#define CAN_BUFFER(n)  ((n) <= (8 * sizeof(machine_word_t)) - 15)
 
 /*
  * Initialize the output bitstream.
@@ -994,6 +996,8 @@ lzx_write_sequences(struct lzx_output_bitstream *os, int block_type,
                        if (!CAN_BUFFER(MAX_MATCH_BITS))
                                lzx_flush_bits(os, ALIGNED_CODEWORD_LIMIT);
                } else {
+                       STATIC_ASSERT(CAN_BUFFER(17));
+
                        lzx_add_bits(os, extra_bits, num_extra_bits);
                        if (!CAN_BUFFER(MAX_MATCH_BITS))
                                lzx_flush_bits(os, 17);
@@ -1809,7 +1813,7 @@ lzx_compress_near_optimal(struct lzx_compressor *c,
                        if (unlikely(max_len > in_end - in_next)) {
                                max_len = in_end - in_next;
                                nice_len = min(max_len, nice_len);
-                               if (unlikely(max_len < 5)) {
+                               if (unlikely(max_len < BT_MATCHFINDER_REQUIRED_NBYTES)) {
                                        in_next++;
                                        cache_ptr->length = 0;
                                        cache_ptr++;
@@ -1849,7 +1853,7 @@ lzx_compress_near_optimal(struct lzx_compressor *c,
                                        if (unlikely(max_len > in_end - in_next)) {
                                                max_len = in_end - in_next;
                                                nice_len = min(max_len, nice_len);
-                                               if (unlikely(max_len < 5)) {
+                                               if (unlikely(max_len < BT_MATCHFINDER_REQUIRED_NBYTES)) {
                                                        in_next++;
                                                        cache_ptr->length = 0;
                                                        cache_ptr++;