From: Nathan Moinvaziri <nathan@nathanm.com>
Date: Fri, 4 Jun 2021 22:27:26 +0000 (-0700)
Subject: Calculate from and out buffer advance only once in chunkcopy.
X-Git-Tag: 2.1.0-beta1~570
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=76b9605f80b697ab3c527cb8638e6340e0e07ce4;p=thirdparty%2Fzlib-ng.git

Calculate from and out buffer advance only once in chunkcopy.
---

diff --git a/chunkset_tpl.h b/chunkset_tpl.h
index ae049e7e7..55e07088c 100644
--- a/chunkset_tpl.h
+++ b/chunkset_tpl.h
@@ -19,11 +19,11 @@ Z_INTERNAL uint32_t CHUNKSIZE(void) {
    reliable. */
 Z_INTERNAL uint8_t* CHUNKCOPY(uint8_t *out, uint8_t const *from, unsigned len) {
     chunk_t chunk;
-    --len;
+    int32_t align = (--len % sizeof(chunk_t)) + 1;
     loadchunk(from, &chunk);
     storechunk(out, &chunk);
-    out += (len % sizeof(chunk_t)) + 1;
-    from += (len % sizeof(chunk_t)) + 1;
+    out += align;
+    from += align;
     len /= sizeof(chunk_t);
     while (len > 0) {
         loadchunk(from, &chunk);