MSSLinux: early detect DISPLAY to stop before all operations

BoboTiG · BoboTiG · commit 526e586d7970 · 2015-05-02T08:26:16.000+02:00
diff --git a/mss.py b/mss.py
@@ -303,6 +303,17 @@ def __del__(self):
     def __init__(self):
         ''' GNU/Linux initialisations '''
 
+        disp = None
+        self.display = None
+        try:
+            if sys.version > '3':
+                disp = bytes(environ['DISPLAY'], 'utf-8')
+            else:
+                disp = environ['DISPLAY']
+        except KeyError:
+            err = 'MSS: $DISPLAY not set. Stopping to prevent segfault.'
+            raise ScreenshotError(err)
+
         x11 = find_library('X11')
         if not x11:
             raise ScreenshotError('MSS: no X11 library found.')
@@ -316,17 +327,6 @@ def __init__(self):
         self._set_argtypes()
         self._set_restypes()
 
-        disp = None
-        self.display = None
-        try:
-            if sys.version > '3':
-                disp = bytes(environ['DISPLAY'], 'utf-8')
-            else:
-                disp = environ['DISPLAY']
-        except KeyError:
-            err = 'MSS: $DISPLAY not set. Stopping to prevent segfault.'
-            raise ScreenshotError(err)
-
         # At this point, if there is no running server, it could end on
         # a segmentation fault. And we cannot catch it.
         self.display = self.xlib.XOpenDisplay(disp)
