From: R.J.V. Bertin <rjvbertin@gmail.com>
Date: Tue, 23 May 2017 17:46:55 +0000 (+0200)
Subject: ZLIB_COMPAT: add an extra 32 bits of padding in z_stream
X-Git-Tag: 1.9.9-b1~660^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=71b6bbe4fd7149cde19f80cc684354c88c92f233;p=thirdparty%2Fzlib-ng.git

ZLIB_COMPAT: add an extra 32 bits of padding in z_stream

zlib "stock" uses an "uLong" for zstream::adler, meaning 4 bytes in 64
bit bits. The padding makes zlib-ng a drop-in replacement for libz; without,
the deflateInit2_() function returns a version error when called from
dependents that were built against "stock" zlib.

Committed from host : Portia.local
---

diff --git a/zlib.h b/zlib.h
index 05b28c2f6..f7b460a6d 100644
--- a/zlib.h
+++ b/zlib.h
@@ -109,6 +109,9 @@ typedef struct z_stream_s {
     int                   data_type;  /* best guess about the data type: binary or text
                                          for deflate, or the decoding state for inflate */
     uint32_t              adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
+#if defined(ZLIB_COMPAT) && defined(X86_64)
+    uint32_t              padding;    /* pad out to the same size as the zlib struct */
+#endif
     unsigned long         reserved;   /* reserved for future use */
 } z_stream;