ecore_evas_x: add safety check for data in converterdevs/bu5hm4n/work_dnd

since the existance of seleciton manager, the converter callbacks from
ecore_x are expecting custom struct pointers. However, enlightenment
never updated to use the elm dnd API for client side usages. Which
results in the fact that sometimes, when a client sents Notify, and
e_dnd is active, that this converter is executed with the wrong data.

With this commit the data passed in is ensured to have the correct magic
number. The proper solution for this would either be registering the
correct converters in enlightenment, or update to elm_drag. However,
since the continues cried river over the last 5 days has raised enough
hydro power to add these changes. This leaves us with just one question:
How was it possible to generate so many messages about a problem that
can be solved in a fraction of charaters that have been written?

fixes <a-issue-that-was-never-created>

Differential Revision: https://phab.enlightenment.org/D11701

1 files changed, 9 insertions, 0 deletions

diff --git a/src/modules/ecore_evas/engines/x/ecore_evas_x.c b/src/modules/ecore_evas/engines/x/ecore_evas_x.c
index a107f66a6d..1a0ae1f4b8 100644
--- a/src/modules/ecore_evas/engines/x/ecore_evas_x.c
+++ b/src/modules/ecore_evas/engines/x/ecore_evas_x.c
@@ -49,6 +49,8 @@
 # endif
 #endif /* ! _WIN32 */
 
+#define ECORE_EVAS_X11_SELECTION 0x7F
+
 #define EDBG(...)                                                       \
   EINA_LOG(_ecore_evas_log_dom, EINA_LOG_LEVEL_DBG + 1, __VA_ARGS__);
 
@@ -75,6 +77,7 @@ static Eina_Bool wm_exists;
 typedef struct _Ecore_Evas_Engine_Data_X11 Ecore_Evas_Engine_Data_X11;
 
 typedef struct {
+   EINA_MAGIC;
    Ecore_Evas_Selection_Callbacks callbacks;
    Ecore_Evas_Selection_Buffer buffer;
    Ecore_Evas *ee;
@@ -4053,6 +4056,11 @@ _eina_content_converter(char *target, void *data, int size EINA_UNUSED, void **d
 {
    Ecore_Evas_X11_Selection_Data *sdata = data;
    Eina_Bool ret = EINA_FALSE;;
+
+   if (size != sizeof(Ecore_Evas_X11_Selection_Data)) return EINA_FALSE;
+
+   if (!EINA_MAGIC_CHECK(sdata, ECORE_EVAS_X11_SELECTION)) return EINA_FALSE;
+
    if (eina_streq(target, "TARGETS") || eina_streq(target, "ATOM"))
      {
         //list all available types that we have currently
@@ -4327,6 +4335,7 @@ _ecore_evas_x_selection_window_init(Ecore_Evas *ee)
         ecore_x_fixes_window_selection_notification_request(ee->prop.window, ecore_evas_selection_to_atom[i]);
         edata->selection_data[i].ee = ee;
         edata->selection_data[i].buffer = i;
+        EINA_MAGIC_SET(&edata->selection_data[i], ECORE_EVAS_X11_SELECTION);
      }
    ecore_x_dnd_aware_set(ee->prop.window, EINA_TRUE);
    edata->init_job = ecore_job_add(_deliver_selection_changed, ee);