SDL: win32: Fix composition UI being displayed when IME is disabled (a849c)

From a849c4d36155ca527d44ae6209781f64ff536eae Mon Sep 17 00:00:00 2001
From: Cameron Gutman <[EMAIL REDACTED]>
Date: Sat, 14 Feb 2026 15:29:12 -0600
Subject: [PATCH] win32: Fix composition UI being displayed when IME is
 disabled

(cherry picked from commit 8535936401edd9605af706db57158fe1c7199ae8)
---
 src/video/windows/SDL_windowskeyboard.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/video/windows/SDL_windowskeyboard.c b/src/video/windows/SDL_windowskeyboard.c
index 698ae5d75a82a..42fb066c42a65 100644
--- a/src/video/windows/SDL_windowskeyboard.c
+++ b/src/video/windows/SDL_windowskeyboard.c
@@ -1072,6 +1072,14 @@ bool WIN_HandleIMEMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM *lParam, SD
         *lParam &= element_mask;
 
         return false;
+    } else if (msg == WM_IME_STARTCOMPOSITION) {
+        SDL_DebugIMELog("WM_IME_STARTCOMPOSITION");
+        if (videodata->ime_internal_composition) {
+            // Windows may still display a composition dialog even with
+            // ISC_SHOWUICOMPOSITIONWINDOW cleared, so trap the message
+            // here to prevent that (even when the IME is disabled).
+            return true;
+        }
     }
 
     if (!videodata->ime_initialized || !videodata->ime_available || !videodata->ime_enabled) {
@@ -1099,12 +1107,6 @@ bool WIN_HandleIMEMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM *lParam, SD
         SDL_DebugIMELog("WM_INPUTLANGCHANGE");
         IME_InputLangChanged(videodata);
         break;
-    case WM_IME_STARTCOMPOSITION:
-        SDL_DebugIMELog("WM_IME_STARTCOMPOSITION");
-        if (videodata->ime_internal_composition) {
-            trap = true;
-        }
-        break;
     case WM_IME_COMPOSITION:
         SDL_DebugIMELog("WM_IME_COMPOSITION %x", lParam);
         if (videodata->ime_internal_composition) {