[PATCH] Check return value of wl_cursor functions

[Hardening]

This patch adds checks for themes and cursors returned by wl_cursor functions.
---
 clients/simple-egl.c     | 10 ++++++++++
 clients/window.c         |  4 ++++
 src/compositor-wayland.c |  7 ++++++-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/clients/simple-egl.c b/clients/simple-egl.c
index a6deff6..410e3ab 100644
--- a/clients/simple-egl.c
+++ b/clients/simple-egl.c
@@ -501,6 +501,8 @@ pointer_handle_enter(void *data, struct wl_pointer *pointer,
 	else if (cursor) {
 		image = display->default_cursor->images[0];
 		buffer = wl_cursor_image_get_buffer(image);
+		if (!buffer)
+			return;
 		wl_pointer_set_cursor(pointer, serial,
 				      display->cursor_surface,
 				      image->hotspot_x,
@@ -715,8 +717,16 @@ registry_handle_global(void *data, struct wl_registry *registry,
 		d->shm = wl_registry_bind(registry, name,
 					  &wl_shm_interface, 1);
 		d->cursor_theme = wl_cursor_theme_load(NULL, 32, d->shm);
+		if (!d->cursor_theme) {
+			fprintf(stderr, "unable to load default theme\n");
+			return;
+		}
 		d->default_cursor =
 			wl_cursor_theme_get_cursor(d->cursor_theme, "left_ptr");
+		if (!d->default_cursor) {
+			fprintf(stderr, "unable to load default left pointer\n");
+			// TODO: abort ?
+		}
 	}
 }
 
diff --git a/clients/window.c b/clients/window.c
index 3136a7d..96b1731 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -1280,6 +1280,10 @@ create_cursors(struct display *display)
 	weston_config_destroy(config);
 
 	display->cursor_theme = wl_cursor_theme_load(theme, size, display->shm);
+	if (!display->cursor_theme) {
+		fprintf(stderr, "could not load theme '%s'\n", theme);
+		return;
+	}
 	free(theme);
 	display->cursors =
 		xmalloc(ARRAY_LENGTH(cursors) * sizeof display->cursors[0]);
diff --git a/src/compositor-wayland.c b/src/compositor-wayland.c
index 238946b..7d9e01b 100644
--- a/src/compositor-wayland.c
+++ b/src/compositor-wayland.c
@@ -968,7 +968,8 @@ input_set_cursor(struct wayland_input *input)
 
 	image = input->compositor->cursor->images[0];
 	buffer = wl_cursor_image_get_buffer(image);
-
+	if (!buffer)
+		return;
 
 	wl_pointer_set_cursor(input->parent.pointer, input->enter_serial,
 			      input->parent.cursor.surface,
@@ -1428,6 +1429,10 @@ create_cursor(struct wayland_compositor *c, struct weston_config *config)
 	weston_config_section_get_int(s, "cursor-size", &size, 32);
 
 	c->cursor_theme = wl_cursor_theme_load(theme, size, c->parent.shm);
+	if (!c->cursor_theme) {
+		fprintf(stderr, "could not load cursor theme\n");
+		return;
+	}
 
 	free(theme);
 
-- 
1.8.1.2