diff -Naru xz-5.2.3/src/liblzma/lz/lz_encoder_mf.c xz-5.2.3.tpg/src/liblzma/lz/lz_encoder_mf.c
--- xz-5.2.3/src/liblzma/lz/lz_encoder_mf.c	2016-12-30 11:08:20.000000000 +0000
+++ xz-5.2.3.tpg/src/liblzma/lz/lz_encoder_mf.c	2017-10-23 15:45:34.970539050 +0000
@@ -464,22 +464,22 @@
 
 	uint32_t len0 = 0;
 	uint32_t len1 = 0;
+	uint32_t len2 = 0;
 
 	while (true) {
 		const uint32_t delta = pos - cur_match;
+		uint32_t len = len2;
 		if (depth-- == 0 || delta >= cyclic_size) {
 			*ptr0 = EMPTY_HASH_VALUE;
 			*ptr1 = EMPTY_HASH_VALUE;
 			return matches;
 		}
 
+		const uint8_t *const pb = cur - delta;
 		uint32_t *const pair = son + ((cyclic_pos - delta
 				+ (delta > cyclic_pos ? cyclic_size : 0))
 				<< 1);
 
-		const uint8_t *const pb = cur - delta;
-		uint32_t len = my_min(len0, len1);
-
 		if (pb[len] == cur[len]) {
 			len = lzma_memcmplen(pb, cur, len + 1, len_limit);
 
@@ -502,11 +502,13 @@
 			ptr1 = pair + 1;
 			cur_match = *ptr1;
 			len1 = len;
+			len2 = my_min(len0, len1);
 		} else {
 			*ptr0 = cur_match;
 			ptr0 = pair;
 			cur_match = *ptr0;
 			len0 = len;
+			len2 = my_min(len0, len1);
 		}
 	}
 }