[ostree] checksumutils: Support splicing stream to arbitrary checksum type

[Colin Walters <walters src gnome org>]

commit 9b6b352181e681fb5f5808d749ea1efb91f0e9cc
Author: Colin Walters <walters verbum org>
Date:   Wed Jan 14 22:01:54 2015 -0500

    checksumutils: Support splicing stream to arbitrary checksum type
    
    This will be used later by the metalink code; you can splice with a
    NULL output stream to an arbitrary GChecksum instead of just a SHA256
    one.

 src/libotutil/ot-checksum-utils.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/libotutil/ot-checksum-utils.c b/src/libotutil/ot-checksum-utils.c
index b728992..c1335fa 100644
--- a/src/libotutil/ot-checksum-utils.c
+++ b/src/libotutil/ot-checksum-utils.c
@@ -92,7 +92,7 @@ ot_gio_splice_update_checksum (GOutputStream  *out,
         }
       while (bytes_read > 0);
     }
-  else
+  else if (out != NULL)
     {
       if (g_output_stream_splice (out, in, 0, cancellable, error) < 0)
         goto out;