Fix inflateInit2() bug when windowBits is 16 or 32.

A windowBits value of 0, 16, or 32 gets the window bits from the
zlib header.  However there is no zlib header for 16, or for 32
when the input is gzip.  This commit sets the window bits for
inflate to 15 if a gzip stream is detected and windowBits was 16
or 32.

diff --git a/inflate.c b/inflate.c
index 82e39be1f71d8d0d284de74a5d653044e578b9d3..2889e3a07d6d425946fc807f0be6b9156ecc1444 100644 (file)
--- a/inflate.c
+++ b/inflate.c
@@ -645,6 +645,8 @@ int flush;
             NEEDBITS(16);
 #ifdef GUNZIP
             if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                if (state->wbits == 0)
+                    state->wbits = 15;
                 state->check = crc32(0L, Z_NULL, 0);
                 CRC2(state->check, hold);
                 INITBITS();