[mutter] screen-cast/src: Always first set spa buffer data to NULL

[Marge Bot <marge-bot src gnome org>]

commit ca95ccdef08ee7c1e6da6982ec47b2a78afdd3d2
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Feb 1 18:32:33 2021 +0100

    screen-cast/src: Always first set spa buffer data to NULL
    
    We use that elsewhere for sanity checking, and it's not initialized to
    anything, so might be pointing to invalid memory if buffer allocation
    failed.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1697>

 src/backends/meta-screen-cast-stream-src.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/backends/meta-screen-cast-stream-src.c b/src/backends/meta-screen-cast-stream-src.c
index 3b09316487..5d3440e5db 100644
--- a/src/backends/meta-screen-cast-stream-src.c
+++ b/src/backends/meta-screen-cast-stream-src.c
@@ -745,6 +745,7 @@ on_stream_add_buffer (void             *data,
 
   spa_data[0].mapoffset = 0;
   spa_data[0].maxsize = stride * priv->video_format.size.height;
+  spa_data[0].data = NULL;
 
   dmabuf_handle =
     meta_screen_cast_create_dma_buf_handle (screen_cast,
@@ -756,7 +757,6 @@ on_stream_add_buffer (void             *data,
       spa_data[0].type = SPA_DATA_DmaBuf;
       spa_data[0].flags = SPA_DATA_FLAG_READWRITE;
       spa_data[0].fd = cogl_dma_buf_handle_get_fd (dmabuf_handle);
-      spa_data[0].data = NULL;
 
       g_hash_table_insert (priv->dmabuf_handles,
                            GINT_TO_POINTER (spa_data[0].fd),