streams: regression: gc issue in get_string_from_stream.

* stream.c (get_string_from_stream_common): The so->buf = 0
assignment must precede the call to string_own(buf), because
the string out stream object may already be garbage, and
the string_own call will reclaim it. If we don't null out
the buffer, the string will get ownership of a freed buffer.
This reproduced in the CSV test case on MacOS Lion, 32 bit x86.

1 files changed, 1 insertions, 1 deletions

diff --git a/stream.c b/stream.c
index a9f37427..8e4f8ec6 100644
--- a/stream.c
+++ b/stream.c
@@ -2724,8 +2724,8 @@ val get_string_from_stream_common(val stream, val copy_p_in)
       if (waste >= 128 && so->size - so->len > so->len / 4)
         buf = coerce(wchar_t *, chk_realloc(coerce(mem_t *, so->buf),
                                             (so->len + 1) * sizeof *so->buf));
-      out = string_own(buf);
       so->buf = 0;
+      out = string_own(buf);
     }
 
     return out;