From: Yann Collet <yann.collet.73@gmail.com>
Date: Wed, 3 Aug 2016 01:36:03 +0000 (+0200)
Subject: fixed dictionary generation, reported by Bartosz Taudul
X-Git-Tag: v0.8.1^2~38
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0b4a2d40f6a6e099e665fc241cd4cbb16a0920b;p=thirdparty%2Fzstd.git

fixed dictionary generation, reported by Bartosz Taudul
---

diff --git a/lib/dictBuilder/zdict.c b/lib/dictBuilder/zdict.c
index e30168cbd..a18ab4469 100644
--- a/lib/dictBuilder/zdict.c
+++ b/lib/dictBuilder/zdict.c
@@ -332,12 +332,13 @@ static dictItem ZDICT_analyzePos(
         } while (length >=MINMATCHLENGTH);
 
         /* look backward */
-        do {
-            length = ZDICT_count(b + pos, b + suffix[start-1]);
-            if (length >= LLIMIT) length = LLIMIT-1;
-            lengthList[length]++;
-            if (length >=MINMATCHLENGTH) start--;
-        } while(length >= MINMATCHLENGTH);
+		length = MINMATCHLENGTH;
+		while ((length >= MINMATCHLENGTH) & (start > 0)) {
+			length = ZDICT_count(b + pos, b + suffix[start - 1]);
+			if (length >= LLIMIT) length = LLIMIT - 1;
+			lengthList[length]++;
+			if (length >= MINMATCHLENGTH) start--;
+		}
 
         /* largest useful length */
         memset(cumulLength, 0, sizeof(cumulLength));