screenshot: Add null check for defending null-dereference

issue step:
 1. efl_util_screenshot_initialize() failed.
 2. But user call efl_util_screenshot_take_tbm_surface() with NULL
 3. Null dereference in 1501 line

Change-Id: I1e88264b0cd6750a2b7ccd316d2f31ea547d5795

diff --git a/src/efl_util.c b/src/efl_util.c
index 4ad4c79..9d7f1a4 100644 (file)
--- a/src/efl_util.c
+++ b/src/efl_util.c
@@ -1485,7 +1485,7 @@ efl_util_screenshot_take_tbm_surface(efl_util_screenshot_h screenshot)
    Efl_Util_Wl_Output_Info *output;
    int ret = 0;
 
-   if (screenshot != g_screenshot)
+   if (!screenshot || (screenshot != g_screenshot))
      {
         set_last_result(EFL_UTIL_ERROR_INVALID_PARAMETER);
         return NULL;