Merge branch 'uli42-pr/fix_xkb_crash' into 3.6.x

nx-X11/lib/src/xkb/XKBBind.c

@@ -108,7 +108,21 @@ XKeycodeToKeysym(Display *dpy,
 
     _XkbCheckPendingRefresh(dpy, dpy->xkb_info);
 
+#ifdef NX_TRANS_SOCKET
+    /*
+       check again, we have seen cases where the connection broke
+       during CheckPendingEvents(), followed by a crash when accessing
+       dpy. See https://github.com/ArcticaProject/nx-libs/issues/801
+    */
+    if (_XkbUnavailable(dpy))
+        return _XKeycodeToKeysym(dpy, kc, col);
+#endif
+
     xkb = dpy->xkb_info->desc;
+#ifdef NX_TRANS_SOCKET
+    if (xkb == NULL)
+        return _XKeycodeToKeysym(dpy, kc, col);
+#endif
     if ((kc < xkb->min_key_code) || (kc > xkb->max_key_code))
         return NoSymbol;
 

nx-X11/programs/Xserver/xkb/xkbUtils.c

@@ -685,6 +685,10 @@ unsigned	act;
 	    else group= newGroup;
 	}
 	else {
+#ifdef NXAGENT_SERVER
+	  /* we have seen division by zero here */
+	  if (ctrls->num_groups != 0)
+#endif
 	    group%= ctrls->num_groups;
 	}
     }