commit e54e1299404101a5a9d0cf5e45512b543967f958

Author: Mark Adler <madler@alumni.caltech.edu>

Date: Sat Sep 5 17:45:55 2015 -0700

Avoid shifts of negative values inflateMark().

The C standard says that bit shifts of negative integers is

undefined. This casts to unsigned values to assure a known

result.

diff --git a/inflate.c b/inflate.c

index 2889e3a..a718416 100644

--- a/inflate.c

+++ b/inflate.c

@@ -1506,9 +1506,10 @@ z_streamp strm;

{

struct inflate_state FAR *state;

- if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;

+ if (strm == Z_NULL || strm->state == Z_NULL)

+ return (long)(((unsigned long)0 - 1) << 16);

state = (struct inflate_state FAR *)strm->state;

- return ((long)(state->back) << 16) +

+ return (long)(((unsigned long)((long)state->back)) << 16) +

(state->mode == COPY ? state->length :

(state->mode == MATCH ? state->was - state->length : 0));

}