Handle some crashes shown up by quick_window test

If the window is deleted very quickly after it is created, we might still be
in xcwm_window_create(), trying to obtain window information.  Make sure that
we just return NULL if the window no longer exists...

2 files changed, 9 insertions, 3 deletions

diff --git a/src/libxcwm/image.c b/src/libxcwm/image.c
index 8389720..eed868e 100644
--- a/src/libxcwm/image.c
+++ b/src/libxcwm/image.c
@@ -44,6 +44,9 @@ xcwm_image_copy_full(xcwm_window_t *window)
     geom_reply = _xcwm_get_window_geometry(window->context->conn,
                                            window->window_id);
 
+    if (!geom_reply)
+        return NULL;
+
     xcb_flush(window->context->conn);
     /* Get the full image of the window */
     image = xcb_image_get(window->context->conn,
diff --git a/src/libxcwm/window.c b/src/libxcwm/window.c
index 68c725a..030a27a 100644
--- a/src/libxcwm/window.c
+++ b/src/libxcwm/window.c
@@ -99,6 +99,12 @@ _xcwm_window_create(xcwm_context_t *context, xcb_window_t new_window,
         _xcwm_get_window_attributes(context->conn, new_window);
     if ((!attrs) || (attrs->_class == XCB_WINDOW_CLASS_INPUT_ONLY))
         return NULL;
+
+    xcb_get_geometry_reply_t *geom;
+    geom = _xcwm_get_window_geometry(context->conn, new_window);
+    if (!geom)
+        return NULL;
+
     /* allocate memory for new xcwm_window_t and rectangles */
     xcwm_window_t *window = malloc(sizeof(xcwm_window_t));
     assert(window);
@@ -109,9 +115,6 @@ _xcwm_window_create(xcwm_context_t *context, xcb_window_t new_window,
     window->sizing = calloc(1, sizeof(*window->sizing));
     assert(window->dmg_bounds);;
 
-    xcb_get_geometry_reply_t *geom;
-    geom = _xcwm_get_window_geometry(context->conn, new_window);
-
     /* set any available values from xcb_create_notify_event_t object pointer
        and geom pointer */
     window->context = context;