From: Nathan Moinvaziri <nathan@nathanm.com>
Date: Thu, 4 Jun 2020 19:57:24 +0000 (-0700)
Subject: Only set current_match to literal if hash_head == 0.
X-Git-Tag: 1.9.9-b1~183
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=712dd227049ea95fc6a43f00daab64c5490e1af2;p=thirdparty%2Fzlib-ng.git

Only set current_match to literal if hash_head == 0.
---

diff --git a/deflate_medium.c b/deflate_medium.c
index d0d8ed6c..c043537f 100644
--- a/deflate_medium.c
+++ b/deflate_medium.c
@@ -196,16 +196,12 @@ ZLIB_INTERNAL block_state deflate_medium(deflate_state *s, int flush) {
         if (next_match.match_length > 0) {
             current_match = next_match;
             next_match.match_length = 0;
-
         } else {
             hash_head = 0;
             if (s->lookahead >= MIN_MATCH) {
                 hash_head = functable.quick_insert_string(s, s->strstart);
             }
 
-            /* set up the initial match to be a 1 byte literal */
-            current_match.match_start = 0;
-            current_match.match_length = 1;
             current_match.strstart = s->strstart;
             current_match.orgstart = current_match.strstart;
 
@@ -226,6 +222,10 @@ ZLIB_INTERNAL block_state deflate_medium(deflate_state *s, int flush) {
                     /* this can happen due to some restarts */
                     current_match.match_length = 1;
                 }
+            } else {
+                /* Set up the match to be a 1 byte literal */
+                current_match.match_start = 0;
+                current_match.match_length = 1;
             }
         }
 
@@ -236,9 +236,6 @@ ZLIB_INTERNAL block_state deflate_medium(deflate_state *s, int flush) {
             s->strstart = current_match.strstart + current_match.match_length;
             hash_head = functable.quick_insert_string(s, s->strstart);
 
-            /* set up the initial match to be a 1 byte literal */
-            next_match.match_start = 0;
-            next_match.match_length = 1;
             next_match.strstart = s->strstart;
             next_match.orgstart = next_match.strstart;
 
@@ -260,9 +257,13 @@ ZLIB_INTERNAL block_state deflate_medium(deflate_state *s, int flush) {
                     next_match.match_length = 1;
                 else
                     fizzle_matches(s, &current_match, &next_match);
+            } else {
+                /* Set up the match to be a 1 byte literal */
+                next_match.match_start = 0;
+                next_match.match_length = 1;
             }
-            s->strstart = current_match.strstart;
 
+            s->strstart = current_match.strstart;
         } else {
             next_match.match_length = 0;
         }