gl-renderer: Add EGL_IMAGE_PRESERVED_KHR to our attributes

So, turns out the GL implementation is allowed to destroy EGLImage
sources if this isn't set. Apparently none we've ever been tested on do
this, but it looks like we should be setting this anyway.

Signed-off-by: Derek Foreman <derek.foreman@collabora.com>

libweston/renderer-gl/gl-renderer.c

@@ -2100,7 +2100,7 @@ gl_renderer_attach_egl(struct weston_surface *es, struct weston_buffer *buffer,
 	struct weston_compositor *ec = es->compositor;
 	struct gl_renderer *gr = get_renderer(ec);
 	struct gl_surface_state *gs = get_surface_state(es);
-	EGLint attribs[3];
+	EGLint attribs[5];
 	GLenum target;
 	int i, num_planes;
 
@@ -2153,7 +2153,10 @@ gl_renderer_attach_egl(struct weston_surface *es, struct weston_buffer *buffer,
 	for (i = 0; i < num_planes; i++) {
 		attribs[0] = EGL_WAYLAND_PLANE_WL;
 		attribs[1] = i;
-		attribs[2] = EGL_NONE;
+		attribs[2] = EGL_IMAGE_PRESERVED_KHR;
+		attribs[3] = EGL_TRUE;
+		attribs[4] = EGL_NONE;
+
 		gs->images[i] = egl_image_create(gr,
 						 EGL_WAYLAND_BUFFER_WL,
 						 buffer->legacy_buffer,
@@ -2187,7 +2190,7 @@ import_simple_dmabuf(struct gl_renderer *gr,
                      struct dmabuf_attributes *attributes)
 {
 	struct egl_image *image;
-	EGLint attribs[50];
+	EGLint attribs[52];
 	int atti = 0;
 	bool has_modifier;
 
@@ -2205,6 +2208,8 @@ import_simple_dmabuf(struct gl_renderer *gr,
 	attribs[atti++] = attributes->height;
 	attribs[atti++] = EGL_LINUX_DRM_FOURCC_EXT;
 	attribs[atti++] = attributes->format;
+	attribs[atti++] = EGL_IMAGE_PRESERVED_KHR;
+	attribs[atti++] = EGL_TRUE;
 
 	if (attributes->modifier[0] != DRM_FORMAT_MOD_INVALID) {
 		if (!gr->has_dmabuf_import_modifiers)