From: Mark Adler <madler@alumni.caltech.edu>
Date: Sun, 16 Apr 2017 15:35:33 +0000 (-0700)
Subject: Handle case where inflateSync used when header never processed.
X-Git-Tag: 1.9.9-b1~585
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3cbd82cffce0d0f9021fc2f3a715a27f3edddd5b;p=thirdparty%2Fzlib-ng.git

Handle case where inflateSync used when header never processed.

If zlib and/or gzip header processing was requested, but a header
was never provided and inflateSync was used successfully, then the
inflate state would be inconsistent, trying to compute a check
value but with no flags set. This commit sets the inflate mode to
raw in this case, since there is no other assumption that can be
made if a header was requested but never seen.
---

diff --git a/inflate.c b/inflate.c
index cb84adb6d..d2e621eaa 100644
--- a/inflate.c
+++ b/inflate.c
@@ -1409,6 +1409,8 @@ int ZEXPORT PREFIX(inflateSync)(PREFIX3(stream) *strm) {
     /* return no joy or set up to restart inflate() on a new block */
     if (state->have != 4)
         return Z_DATA_ERROR;
+    if (state->mode == HEAD)
+        state->wrap = 0;    /* never processed header, so assume raw */
     in = strm->total_in;
     out = strm->total_out;
     PREFIX(inflateReset)(strm);