Take the window border size into account when positioning the IBus candidate list.

src/core/linux/SDL_ibus.c

@@ -22,10 +22,16 @@
 
 #ifdef HAVE_IBUS_IBUS_H
 #include "SDL.h"
+#include "SDL_syswm.h"
 #include "SDL_ibus.h"
 #include "SDL_dbus.h"
 #include "../../video/SDL_sysvideo.h"
 #include "../../events/SDL_keyboard_c.h"
+
+#if SDL_VIDEO_DRIVER_X11
+    #include "../../video/x11/SDL_x11video.h"
+#endif
+
 #include <sys/inotify.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -545,9 +551,31 @@ SDL_IBus_UpdateTextRect(SDL_Rect *rect)
     SDL_Window *focused_win = SDL_GetFocusWindow();
 
     if(!focused_win) return;
-
+    
+    SDL_SysWMinfo info;
+    SDL_VERSION(&info.version);
+    
+    if(!SDL_GetWindowWMInfo(focused_win, &info)) return;
+    
     int x = 0, y = 0;
+    
     SDL_GetWindowPosition(focused_win, &x, &y);
+   
+#if SDL_VIDEO_DRIVER_X11    
+    if(info.subsystem == SDL_SYSWM_X11){
+        SDL_DisplayData *displaydata =
+            (SDL_DisplayData *) SDL_GetDisplayForWindow(focused_win)->driverdata;
+            
+        Display *x_disp = info.info.x11.display;
+        Window x_win = info.info.x11.window;
+        int x_screen = displaydata->screen;
+        Window unused;
+            
+        X11_XTranslateCoordinates(x_disp, x_win, RootWindow(x_disp, x_screen),
+            0, 0, &x, &y, &unused);
+    }
+#endif
+
     x += ibus_cursor_rect.x;
     y += ibus_cursor_rect.y;