KeyboardMap::releaseKeyCharacterMap() detaches JNI threads it did not attach

[QiuYucheng2003]

Describe the bug
KeyboardMap::releaseKeyCharacterMap() always calls JavaVM::DetachCurrentThread() after deleting the KeyCharacterMap global ref. getJNIEnvFromJavaVM() only attaches when GetEnv returns JNI_EDETACHED; if the thread is already attached it just returns the existing JNIEnv and does not record that fact.

The documented call site is a NativeActivity command handler (APP_CMD_INIT_WINDOW / APP_CMD_DESTROY). That thread is already attached by android_native_app_glue before android_main runs, so VSG never attaches it, then releaseKeyCharacterMap() detaches the glue’s attach. Later JNI on the same thread (including the glue’s own cleanup DetachCurrentThread) can then see a detached env.

DeleteGlobalRef itself is paired with NewGlobalRef; the bug is only the unconditional detach.

To Reproduce
This is from source inspection of the documented Android path; no runtime log attached.

1. NativeActivity app using android_native_app_glue.
2. On APP_CMD_INIT_WINDOW, call KeyboardMap::initializeKeyCharacterMap(app->activity->vm) as documented in Android_Window.h.
3. On APP_CMD_DESTROY, call KeyboardMap::releaseKeyCharacterMap().
4. That destroy path detaches the native thread even though VSG did not attach it.

Relevant code:

• https://github.com/vsg-dev/VulkanSceneGraph/blob/master/src/vsg/platform/android/Android_Window.cpp#L295-L349
• https://github.com/vsg-dev/VulkanSceneGraph/blob/master/include/vsg/platform/android/Android_Window.h (initialize after APP_CMD_INIT_WINDOW, release after APP_CMD_DESTROY)

static JNIEnv* getJNIEnvFromJavaVM(JavaVM* vm)
{
    jint ret = vm->GetEnv((void**)&env, JNI_VERSION_1_6);
    if (ret == JNI_EDETACHED)
        ret = vm->AttachCurrentThread(&env, &args);
    // JNI_OK: already attached, no flag returned
    return env;
}

void KeyboardMap::releaseKeyCharacterMap()
{
    if (classKeyCharacterMap)
    {
        JNIEnv* env = getJNIEnvFromJavaVM(javaVM);
        if (env)
        {
            env->DeleteGlobalRef(classKeyCharacterMap);
            classKeyCharacterMap = nullptr;
        }
        javaVM->DetachCurrentThread(); // always, even if this call did not Attach
    }
}

Expected behavior
Detach only if this code attached the thread. getJNIEnvFromJavaVM should return whether it attached (e.g. bool* attached), and releaseKeyCharacterMap should call DetachCurrentThread only when that flag is true. initializeKeyCharacterMap / getUnicodeChar should follow the same rule.

Screenshots
N/A

Desktop (please complete the following information):

• OS: N/A (Android native)
• Browser: N/A
• Version: current master (Android_Window.cpp KeyboardMap JNI helpers)

Smartphone (please complete the following information):

• Device: NativeActivity / android_native_app_glue
• OS: Android
• Browser: N/A
• Version: N/A

Additional context
initializeKeyCharacterMap and getUnicodeChar never detach (attach-and-stay). Combined with an unconditional detach in releaseKeyCharacterMap, the intended NativeActivity usage is the mismatched path, not a rare edge case.