lzms-compress.c: Fix crash on compression levels 1 through 4

lzms_get_near_optimal_item() assumes that nice_match_length >=
min_match_length.

diff --git a/src/lzms-compress.c b/src/lzms-compress.c
index d93ce3d1e5b975af00b188506b9ac540bb7f10f9..b4391c2be9c95b3dda653588f801c4ef6baac60f 100644 (file)
--- a/src/lzms-compress.c
+++ b/src/lzms-compress.c
@@ -1309,7 +1309,8 @@ lzms_build_params(unsigned int compression_level,
                  struct lzms_compressor_params *lzms_params)
 {
        lzms_params->min_match_length  = (compression_level >= 50) ? 2 : 3;
                  struct lzms_compressor_params *lzms_params)
 {
        lzms_params->min_match_length  = (compression_level >= 50) ? 2 : 3;

-       lzms_params->nice_match_length = ((u64)compression_level * 32) / 50;
+       lzms_params->nice_match_length = max(((u64)compression_level * 32) / 50,
+                                            lzms_params->min_match_length);

        lzms_params->max_search_depth  = ((u64)compression_level * 50) / 50;
        lzms_params->optim_array_length = 224 + compression_level * 16;
 }
        lzms_params->max_search_depth  = ((u64)compression_level * 50) / 50;
        lzms_params->optim_array_length = 224 + compression_level * 16;
 }