Change gzread() and related to ignore junk after gzip streams.

Previously the new gz* functions (introduced in 1.2.4) would read and
return raw data after the last gzip stream.  This is inconsistent with
the behavior of gzip and the previous versions of zlib.  Now when one
or more gzip streams have been decoded from the file, which is then
followed by data that is not a gzip stream (as detemined by not finding
the magic header), then that subsequent trailing garbage is ignored,
and no error is returned.

1 files changed, 9 insertions, 0 deletions

diff --git a/gzread.c b/gzread.c
index 8fc2915..213ad8c 100644
--- a/gzread.c
+++ b/gzread.c
@@ -207,6 +207,15 @@ local int gz_head(state)
         }
     }
 
+    /* no gzip header -- if we were decoding gzip before, then this is trailing
+       garbage.  Ignore the trailing garbage and finish. */
+    if (state->direct == 0) {
+        strm->avail_in = 0;
+        state->eof = 1;
+        state->have = 0;
+        return 0;
+    }
+
     /* doing raw i/o, save start of raw data for seeking, copy any leftover
        input to output -- this assumes that the output buffer is larger than
        the input buffer, which also assures space for gzungetc() */