From: Nathan Moinvaziri <nathan@nathanm.com>
Date: Mon, 1 Mar 2021 02:17:04 +0000 (-0800)
Subject: Mod adler and sum2 when calculating adler32 for short lengths.
X-Git-Tag: 2.1.0-beta1~587
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5419d68ea37cdf7740268188535d811d05bf270;p=thirdparty%2Fzlib-ng.git

Mod adler and sum2 when calculating adler32 for short lengths.
---

diff --git a/adler32_p.h b/adler32_p.h
index 7f75c71e2..adcc79f01 100644
--- a/adler32_p.h
+++ b/adler32_p.h
@@ -20,11 +20,9 @@
 
 static inline uint32_t adler32_len_1(uint32_t adler, const unsigned char *buf, uint32_t sum2) {
     adler += buf[0];
-    if (adler >= BASE)
-        adler -= BASE;
+    adler %= BASE;
     sum2 += adler;
-    if (sum2 >= BASE)
-        sum2 -= BASE;
+    sum2 %= BASE;
     return adler | (sum2 << 16);
 }
 
@@ -34,8 +32,7 @@ static inline uint32_t adler32_len_16(uint32_t adler, const unsigned char *buf,
         adler += *buf++;
         sum2 += adler;
     }
-    if (adler >= BASE)
-        adler -= BASE;
+    adler %= BASE;
     sum2 %= BASE;            /* only added so many BASE's */
     return adler | (sum2 << 16);
 }