From: Nathan Moinvaziri <nathan@nathanm.com>
Date: Thu, 2 Jan 2020 15:59:52 +0000 (-0800)
Subject: Removed MAX_DIST2 which is incompatible with zlib when compiled with INFLATE_STRICT... 
X-Git-Tag: 1.9.9-b1~372
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c4eb71b1d51a1c89ebaff0c16af4d2ae54433e7;p=thirdparty%2Fzlib-ng.git

Removed MAX_DIST2 which is incompatible with zlib when compiled with INFLATE_STRICT. It also fixes the check for proper bounds in zng_tr_tally.
---

diff --git a/deflate_medium.c b/deflate_medium.c
index f694facd..4c975ea5 100644
--- a/deflate_medium.c
+++ b/deflate_medium.c
@@ -20,8 +20,6 @@ struct match {
     unsigned int orgstart;
 };
 
-#define MAX_DIST2  ((1 << MAX_WBITS) - MIN_LOOKAHEAD)
-
 static int tr_tally_dist(deflate_state *s, int distance, int length) {
     return zng_tr_tally(s, distance, length);
 }
@@ -162,7 +160,7 @@ static void fizzle_matches(deflate_state *s, struct match *current, struct match
     n = *next;
 
     /* step one: try to move the "next" match to the left as much as possible */
-    limit = next->strstart > MAX_DIST2 ? next->strstart - MAX_DIST2 : 0;
+    limit = next->strstart > MAX_DIST(s) ? next->strstart - MAX_DIST(s) : 0;
 
     match = s->window + n.match_start - 1;
     orig = s->window + n.strstart - 1;
@@ -249,7 +247,7 @@ ZLIB_INTERNAL block_state deflate_medium(deflate_state *s, int flush) {
              * At this point we have always match_length < MIN_MATCH
              */
 
-            if (hash_head != 0 && s->strstart - hash_head <= MAX_DIST2) {
+            if (hash_head != 0 && s->strstart - hash_head <= MAX_DIST(s)) {
                 /* To simplify the code, we prevent matches with the string
                  * of window index 0 (in particular we have to avoid a match
                  * of the string with itself at the start of the input file).
@@ -281,7 +279,7 @@ ZLIB_INTERNAL block_state deflate_medium(deflate_state *s, int flush) {
             /* Find the longest match, discarding those <= prev_length.
              * At this point we have always match_length < MIN_MATCH
              */
-            if (hash_head != 0 && s->strstart - hash_head <= MAX_DIST2) {
+            if (hash_head != 0 && s->strstart - hash_head <= MAX_DIST(s)) {
                 /* To simplify the code, we prevent matches with the string
                  * of window index 0 (in particular we have to avoid a match
                  * of the string with itself at the start of the input file).