Initialise a couple of important values in newly created stream objects

The "modes" and "end_status" values were being left unset by s_init() which
*may* end up causing problems if the stream finalize method gets called
before those values are set by something else.

This stems from oss-fuzz #50898 which we cannot reproduce, but Ken spotted the
potential problem reading the code, so we're putting in a speculative fix.

1 files changed, 2 insertions, 0 deletions

diff --git a/base/stream.c b/base/stream.c
index 6b5847257..5c4c3d1de 100644
--- a/base/stream.c
+++ b/base/stream.c
@@ -110,6 +110,8 @@ s_init(stream *s, gs_memory_t * mem)
     s->prev = s->next = 0;	/* clean for GC */
     s->file_name.data = 0;	/* ibid. */
     s->file_name.size = 0;
+    s->end_status = 0;
+    s->modes = 0;
     s->close_strm = false;	/* default */
     s->close_at_eod = true;	/* default */
     s->cbuf_string_memory = NULL;