window: use different keys for different cairo privates

cairo_surface_t objects have a private set, either struct
shm_surface_data, or struct egl_window_surface_data. Use separate
private keys for each type to avoid mismatch.

This makes display_get_buffer_for_surface() safe, in that it won't
return garbage for an EGL-based cairo surface.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

diff --git a/clients/window.c b/clients/window.c
index 18bacfc..44a057c 100644 (file)
--- a/clients/window.c
+++ b/clients/window.c
@@ -346,7 +346,8 @@ enum window_location {
        WINDOW_CLIENT_AREA = 18,
 };
 
-static const cairo_user_data_key_t surface_data_key;
+static const cairo_user_data_key_t shm_surface_data_key;
+static const cairo_user_data_key_t egl_window_surface_data_key;
 
 #ifdef HAVE_CAIRO_EGL
 
@@ -403,7 +404,8 @@ display_create_egl_window_surface(struct display *display,
                                                        rectangle->width,
                                                        rectangle->height);
 
-       cairo_surface_set_user_data(cairo_surface, &surface_data_key,
+       cairo_surface_set_user_data(cairo_surface,
+                                   &egl_window_surface_data_key,
                                    data, egl_window_surface_data_destroy);
 
        return cairo_surface;
@@ -422,7 +424,7 @@ display_get_buffer_for_surface(struct display *display,
 {
        struct shm_surface_data *data;
 
-       data = cairo_surface_get_user_data (surface, &surface_data_key);
+       data = cairo_surface_get_user_data(surface, &shm_surface_data_key);
 
        return data->buffer;
 }
@@ -559,8 +561,8 @@ display_create_shm_surface_from_pool(struct display *display,
                                                       rectangle->height,
                                                       stride);
 
-       cairo_surface_set_user_data (surface, &surface_data_key,
-                                    data, shm_surface_data_destroy);
+       cairo_surface_set_user_data(surface, &shm_surface_data_key,
+                                   data, shm_surface_data_destroy);
 
        if (flags & SURFACE_OPAQUE)
                format = WL_SHM_FORMAT_XRGB8888;
@@ -609,7 +611,7 @@ display_create_shm_surface(struct display *display,
        }
 
        /* make sure we destroy the pool when the surface is destroyed */
-       data = cairo_surface_get_user_data(surface, &surface_data_key);
+       data = cairo_surface_get_user_data(surface, &shm_surface_data_key);
        data->pool = pool;
 
        return surface;
@@ -844,7 +846,7 @@ window_attach_surface(struct window *window)
 #ifdef HAVE_CAIRO_EGL
        case WINDOW_BUFFER_TYPE_EGL_WINDOW:
                data = cairo_surface_get_user_data(window->cairo_surface,
-                                                  &surface_data_key);
+                                                  &egl_window_surface_data_key);
 
                cairo_gl_surface_swapbuffers(window->cairo_surface);
                wl_egl_window_get_attached_size(data->window,
@@ -902,7 +904,7 @@ window_resize_cairo_window_surface(struct window *window)
        int x, y;
 
        data = cairo_surface_get_user_data(window->cairo_surface,
-                                          &surface_data_key);
+                                          &egl_window_surface_data_key);
 
        window_get_resize_dx_dy(window, &x, &y),
        wl_egl_window_resize(data->window,
@@ -3874,6 +3876,8 @@ display_create(int argc, char *argv[])
 {
        struct display *d;
 
+       assert(&egl_window_surface_data_key != &shm_surface_data_key);
+
        d = malloc(sizeof *d);
        if (d == NULL)
                return NULL;
@@ -4069,7 +4073,7 @@ display_acquire_window_surface(struct display *display,
        }
 
        data = cairo_surface_get_user_data(window->cairo_surface,
-                                          &surface_data_key);
+                                          &egl_window_surface_data_key);
 
        cairo_device_flush(device);
        cairo_device_acquire(device);