From: Hans Kristian Rosbach <hk-git@circlestorm.org>
Date: Sat, 12 Jul 2025 10:48:10 +0000 (+0200)
Subject: Revert "Inserting strings is not slow any longer, remove bypass in deflate_medium()."
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e928d16a68db5c60934db80b3b8ac94907ec065;p=thirdparty%2Fzlib-ng.git

Revert "Inserting strings is not slow any longer, remove bypass in deflate_medium()."

This reverts commit 322753f36e833343ae030e499564691da15eef32.
---

diff --git a/deflate_medium.c b/deflate_medium.c
index ca334e4b..ae7c737e 100644
--- a/deflate_medium.c
+++ b/deflate_medium.c
@@ -63,8 +63,10 @@ static void insert_match(deflate_state *s, struct match match) {
         return;
     }
 
-    /* Insert new strings in the hash table. */
-    if (s->lookahead >= WANT_MIN_MATCH) {
+    /* Insert new strings in the hash table only if the match length
+     * is not too large. This saves time but degrades compression.
+     */
+    if (match.match_length <= 16 * s->max_insert_length && s->lookahead >= WANT_MIN_MATCH) {
         match.match_length--; /* string at strstart already in table */
         match.strstart++;