From e554695638228b846d49657f31eeff0ca4680e8a Mon Sep 17 00:00:00 2001 From: Mark Adler Date: Thu, 15 Dec 2022 09:07:13 -0800 Subject: [PATCH] Fix bug in deflateBound() for level 0 and memLevel 9. memLevel 9 would cause deflateBound() to assume the use of fixed blocks, even if the compression level was 0, which forces stored blocks. That could result in a bound less than the size of the compressed data. Now level 0 always uses the stored blocks bound. --- deflate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/deflate.c b/deflate.c index cd538b8..4a512e1 100644 --- a/deflate.c +++ b/deflate.c @@ -752,7 +752,8 @@ uLong ZEXPORT deflateBound(strm, sourceLen) /* if not default parameters, return one of the conservative bounds */ if (s->w_bits != 15 || s->hash_bits != 8 + 7) - return (s->w_bits <= s->hash_bits ? fixedlen : storelen) + wraplen; + return (s->w_bits <= s->hash_bits && s->level ? fixedlen : storelen) + + wraplen; /* default settings: return tight bound for that case -- ~0.03% overhead plus a small constant */