Otherwise a 0-byte buffer would be allocated, which gives NULL memory when mapped. Thanks to Antonio Morales for finding and reporting the issue. Fixes GHSL-2024-118 Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/3876 Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8041>