From: Nathan Moinvaziri <nathan@solidstatenetworks.com>
Date: Thu, 14 May 2020 04:03:38 +0000 (-0400)
Subject: Check distance in deflate_quick using MAX_DIST(s).
X-Git-Tag: 1.9.9-b1~283
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=81a06e1d5b335f70598fe4492b3f68c6690e5b50;p=thirdparty%2Fzlib-ng.git

Check distance in deflate_quick using MAX_DIST(s).
Added check_match to validate matches when using deflate_quick in debug mode.
---

diff --git a/arch/x86/deflate_quick.c b/arch/x86/deflate_quick.c
index 346b9d57f..26ce0befd 100644
--- a/arch/x86/deflate_quick.c
+++ b/arch/x86/deflate_quick.c
@@ -64,7 +64,7 @@ ZLIB_INTERNAL block_state deflate_quick(deflate_state *s, int flush) {
             hash_head = functable.quick_insert_string(s, s->strstart);
             dist = s->strstart - hash_head;
 
-            if (dist > 0 && (dist-1) < (s->w_size - 1)) {
+            if (dist > 0 && dist < MAX_DIST(s)) {
                 match_len = functable.compare258(s->window + s->strstart, s->window + hash_head);
 
                 if (match_len >= MIN_MATCH) {
@@ -74,6 +74,8 @@ ZLIB_INTERNAL block_state deflate_quick(deflate_state *s, int flush) {
                     if (match_len > MAX_MATCH)
                         match_len = MAX_MATCH;
 
+                    check_match(s, s->strstart, hash_head, match_len);
+
                     zng_tr_emit_dist(s, static_ltree, static_dtree, match_len - MIN_MATCH, dist);
                     s->lookahead -= match_len;
                     s->strstart += match_len;