Avoid a crash when a tray without a menu is clicked on Windows.

[Sackzement]

Creating just a SDL_Tray without a SDL_TrayMenu crashes when the tray icon is clicked.

SDL commit: 17c4bdd

System:
Windows 10
Visual Studio 17 2022
Windows SDK version 10.0.26100.0
target Windows 10.0.19045

Code example

#include <SDL3/SDL.h>
#include <stdio.h>


int main() {
    if (!SDL_Init(SDL_INIT_VIDEO)) {
        printf("%s\n", SDL_GetError());
        return -1;
    }

    SDL_Window* window = SDL_CreateWindow("SDL3_tray_test", 400, 300, 0);
    if (!window) {
        printf("%s\n", SDL_GetError());
        return -1;
    }

    SDL_Renderer* renderer = SDL_CreateRenderer(window, NULL);
    if (!renderer) {
        printf("%s\n", SDL_GetError());
        return -1;
    }

    SDL_Surface* tray_surface = SDL_CreateSurface(1, 1, SDL_PIXELFORMAT_RGBA32);
    if (!tray_surface) {
        printf("%s\n", SDL_GetError());
    }
    else {
        if (!SDL_WriteSurfacePixel(tray_surface, 0, 0, 255, 0, 0, 255)) {
            printf("%s\n", SDL_GetError());
        }
    }

    SDL_Tray* tray = SDL_CreateTray(tray_surface, "tray tooltip");
    if (!tray) {
        printf("%s\n", SDL_GetError());
        return -1;
    }

    if (tray_surface) {
        SDL_DestroySurface(tray_surface);
    }
    
    //// without a tray-menu, program crashes on click
    //SDL_TrayMenu *tray_menu = SDL_CreateTrayMenu(tray);
    //if (!tray_menu) {
    //    printf("%s\n", SDL_GetError());
    //    return -1;
    //}

    bool running = true;
    while (running) {
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
            switch (event.type) {
            case SDL_EVENT_QUIT:
            case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
            case SDL_EVENT_WINDOW_DESTROYED:
                running = false;
            }
        }
        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
        SDL_RenderClear(renderer);
        SDL_RenderPresent(renderer);

        SDL_Delay(10);
    }

    SDL_DestroyTray(tray);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

Exception:

Unhandled exception at 0x00007FFFCB9AD74B (SDL3.dll) in SDL3_tray_test.exe: 0xC000041D: An unhandled exception was encountered during a user callback.

Call Stack:

>	SDL3.dll!TrayWindowProc(HWND__ * hwnd, unsigned int uMsg, unsigned __int64 wParam, __int64 lParam) Line 118	C
 	[External Code]	
 	SDL3.dll!WIN_PumpEvents(SDL_VideoDevice * _this) Line 2430	C
 	SDL3.dll!SDL_PumpEventsInternal(bool push_sentinel) Line 1405	C
 	SDL3.dll!SDL_WaitEventTimeoutNS(SDL_Event * event, __int64 timeoutNS) Line 1580	C
 	SDL3.dll!SDL_PollEvent_REAL(SDL_Event * event) Line 1435	C
 	SDL3.dll!SDL_PollEvent(SDL_Event * a) Line 713	C
 	SDL3_tray_test.exe!main(...) Line 56	C
 	[External Code]	

The crash happens here, where tray->menu is NULL and gets dereferenced:

SDL/src/tray/windows/SDL_tray.c

Line 118 in 17c4bdd

TrackPopupMenu(tray->menu->hMenu, TPM_BOTTOMALIGN | TPM_RIGHTALIGN, GET_X_LPARAM(wParam), GET_Y_LPARAM(wParam), 0, hwnd, NULL);

This commit adds a NULL-check around the function call.

[slouken]

Merged, thanks!