[cairo-output-stream] Guard against destroying the nil streams.

Add a guard to return early if we attempt to call
_cairo_output_stream_destroy() on the nil cairo_output_stream_t streams.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/cairo-output-stream.c b/src/cairo-output-stream.c
index 323bd0645..5bce0e343 100644
--- a/src/cairo-output-stream.c
+++ b/src/cairo-output-stream.c
@@ -166,6 +166,12 @@ _cairo_output_stream_destroy (cairo_output_stream_t *stream)
     if (stream == NULL)
 	return _cairo_error (CAIRO_STATUS_NULL_POINTER);
 
+    if (stream == &_cairo_output_stream_nil ||
+	stream == &_cairo_output_stream_nil_write_error)
+    {
+	return stream->status;
+    }
+
     status = _cairo_output_stream_fini (stream);
     free (stream);