From 6ec72f6b717ef9e2d45ab014b04bcdb1c9bdb964 Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Fri, 20 Jul 2018 12:06:45 +0200
Subject: [PATCH] check for X11_display when using SDL

SDL can be using another video driver
---
 src/readline.c  | 6 ++++++
 src/sdlscreen.c | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/src/readline.c b/src/readline.c
index 662ea8ae..5ba5a75c 100644
--- a/src/readline.c
+++ b/src/readline.c
@@ -437,6 +437,12 @@ bye:
       GFX2_Log(GFX2_ERROR, "Failed to get X11 display and window\n");
       return NULL;
     }
+    if (X11_display == NULL)
+    {
+      char video_driver_name[32];
+      GFX2_Log(GFX2_WARNING, "X11 display is NULL. X11 is needed for Copy/Paste. SDL video driver is currently %s\n", SDL_VideoDriverName(video_driver_name, sizeof(video_driver_name)));
+      return NULL;
+    }
 #endif
     selection = XInternAtom(X11_display, "CLIPBOARD", False);
     selection_owner = XGetSelectionOwner(X11_display, selection);
diff --git a/src/sdlscreen.c b/src/sdlscreen.c
index eb30c8fb..87ccd02d 100644
--- a/src/sdlscreen.c
+++ b/src/sdlscreen.c
@@ -588,6 +588,12 @@ void Allow_drag_and_drop(int flag)
 
   if (GFX2_Get_X11_Display_Window(&display, &window))
   {
+    if (display == NULL)
+    {
+      if (flag)
+        GFX2_Log(GFX2_WARNING, "Drag&Drop with SDL needs the x11 video driver\n");
+      return;
+    }
     XChangeProperty(display, window,
                     XInternAtom(display, "XdndAware", False),
                     XA_ATOM, 32, PropModeReplace, (unsigned char *)&version, 1);