SDL_TextEditingEvent.edit.start will go wrong

[signin0]

Keep pressing the left arrow and the error is 3

#include <SDL2/SDL.h>

int main(int argc, char *argv[]) {
    SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);
    SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
    SDL_CreateWindow("demo", 800, 80, 340, 740,SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_RENDERER_PRESENTVSYNC);
    SDL_Event e;
    while (1) {
        if (SDL_PollEvent(&e)) {
            switch (e.type) {
                case SDL_QUIT:
                    return 0;
                case SDL_TEXTEDITING:
                    SDL_Log("%d|%d|%s\n", e.edit.start, e.edit.length, e.edit.text);
            }
        }
    }
}

It means a's|, but it's actually |a's