3 files changed, 26 insertions, 8 deletions
diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c
index 2dad7e5f..702582ce 100644
--- a/src/liblzma/lz/lz_encoder.c
+++ b/src/liblzma/lz/lz_encoder.c
@@ -293,11 +293,15 @@ lz_encoder_prepare(lzma_mf *mf, const lzma_allocator *allocator,
 		return true;
 	}
 
-	// Calculate the sizes of mf->hash and mf->son and check that
-	// nice_len is big enough for the selected match finder.
-	const uint32_t hash_bytes = lz_options->match_finder & 0x0F;
-	if (hash_bytes > mf->nice_len)
-		return true;
+	// Calculate the sizes of mf->hash and mf->son.
+	//
+	// NOTE: Since 5.3.5beta the LZMA encoder ensures that nice_len
+	// is big enough for the selected match finder. This makes it
+	// easier for applications as nice_len = 2 will always be accepted
+	// even though the effective value can be slightly bigger.
+	const uint32_t hash_bytes
+			= mf_get_hash_bytes(lz_options->match_finder);
+	assert(hash_bytes <= mf->nice_len);
 
 	const bool is_bt = (lz_options->match_finder & 0x10) != 0;
 	uint32_t hs;
diff --git a/src/liblzma/lz/lz_encoder.h b/src/liblzma/lz/lz_encoder.h
index e249beba..41439408 100644
--- a/src/liblzma/lz/lz_encoder.h
+++ b/src/liblzma/lz/lz_encoder.h
@@ -220,6 +220,15 @@ typedef struct {
 // are called `read ahead'.
 
 
+/// Get how many bytes the match finder hashes in its initial step.
+/// This is also the minimum nice_len value with the match finder.
+static inline uint32_t
+mf_get_hash_bytes(lzma_match_finder match_finder)
+{
+	return (uint32_t)match_finder & 0x0F;
+}
+
+
 /// Get pointer to the first byte not ran through the match finder
 static inline const uint8_t *
 mf_ptr(const lzma_mf *mf)
diff --git a/src/liblzma/lzma/lzma_encoder.c b/src/liblzma/lzma/lzma_encoder.c
index 788bcd1f..9a64b71f 100644
--- a/src/liblzma/lzma/lzma_encoder.c
+++ b/src/liblzma/lzma/lzma_encoder.c
@@ -492,7 +492,8 @@ set_lz_options(lzma_lz_options *lz_options, const lzma_options_lzma *options)
 	lz_options->dict_size = options->dict_size;
 	lz_options->after_size = LOOP_INPUT_MAX;
 	lz_options->match_len_max = MATCH_LEN_MAX;
-	lz_options->nice_len = options->nice_len;
+	lz_options->nice_len = my_max(mf_get_hash_bytes(options->mf),
+				options->nice_len);
 	lz_options->match_finder = options->mf;
 	lz_options->depth = options->depth;
 	lz_options->preset_dict = options->preset_dict;
@@ -643,10 +644,14 @@ lzma_lzma_encoder_create(void **coder_ptr,
 			coder->dist_table_size = log_size * 2;
 
 			// Length encoders' price table size
+			const uint32_t nice_len = my_max(
+					mf_get_hash_bytes(options->mf),
+					options->nice_len);
+
 			coder->match_len_encoder.table_size
-				= options->nice_len + 1 - MATCH_LEN_MIN;
+					= nice_len + 1 - MATCH_LEN_MIN;
 			coder->rep_len_encoder.table_size
-				= options->nice_len + 1 - MATCH_LEN_MIN;
+					= nice_len + 1 - MATCH_LEN_MIN;
 			break;
 		}