Windows_IME_Patch.patch

--- a/src/video/windows/SDL_windowskeyboard.c	
+++ a/src/video/windows/SDL_windowskeyboard.c	
@@ -229,28 +229,37 @@ 
 }
 
 void
+WIN_UpdateTextInputRect(SDL_VideoData *videodata)
+{
+    HIMC himc = ImmGetContext(videodata->ime_hwnd_current);
+    if (!himc)
+        return;
+
+    CANDIDATEFORM cf;
+    cf.dwIndex = 0;
+    cf.dwStyle = CFS_EXCLUDE;
+    cf.ptCurrentPos.x = videodata->ime_rect.x;
+    cf.ptCurrentPos.y = videodata->ime_rect.y;
+    cf.rcArea.left = videodata->ime_rect.x;
+    cf.rcArea.top = videodata->ime_rect.y;
+    cf.rcArea.right = videodata->ime_rect.x + videodata->ime_rect.w;
+    cf.rcArea.bottom = videodata->ime_rect.y + videodata->ime_rect.h;
+    ImmSetCandidateWindow(himc, &cf);
+
+    ImmReleaseContext(videodata->ime_hwnd_current, himc);
+}
+
+void
 WIN_SetTextInputRect(_THIS, SDL_Rect *rect)
 {
-    SDL_VideoData *videodata = (SDL_VideoData *)_this->driverdata;
-    HIMC himc = 0;
-
     if (!rect) {
         SDL_InvalidParamError("rect");
         return;
     }
 
+    SDL_VideoData *videodata = (SDL_VideoData *)_this->driverdata;
     videodata->ime_rect = *rect;
-
-    himc = ImmGetContext(videodata->ime_hwnd_current);
-    if (himc)
-    {
-        COMPOSITIONFORM cf;
-        cf.ptCurrentPos.x = videodata->ime_rect.x;
-        cf.ptCurrentPos.y = videodata->ime_rect.y;
-        cf.dwStyle = CFS_FORCE_POSITION;
-        ImmSetCompositionWindow(himc, &cf);
-        ImmReleaseContext(videodata->ime_hwnd_current, himc);
-    }
+    WIN_UpdateTextInputRect(videodata);
 }
 
 #ifdef SDL_DISABLE_WINDOWS_IME
@@ -370,7 +379,8 @@ 
     videodata->ime_available = SDL_TRUE;
     IME_UpdateInputLocale(videodata);
     IME_SetupAPI(videodata);
-    videodata->ime_uiless = UILess_SetupSinks(videodata);
+    // FIXME: the implementation of UILess IME is incomplete so we disable it by commenting this out:
+    //videodata->ime_uiless = UILess_SetupSinks(videodata);
     IME_UpdateInputLocale(videodata);
     IME_Disable(videodata, hwnd);
 }
@@ -882,6 +892,7 @@ 
         *lParam = 0;
         break;
     case WM_IME_STARTCOMPOSITION:
+        WIN_UpdateTextInputRect(videodata);
         trap = SDL_TRUE;
         break;
     case WM_IME_COMPOSITION: