From ccc63521d07a946c1902b79250a52612319b1605 Mon Sep 17 00:00:00 2001
From: Benign X <1341398182@qq.com>
Date: Wed, 20 Dec 2023 14:17:19 +0800
Subject: [PATCH] fix(lv_canvas): fix undefined behavior (#5059)

```bash
Left shift of 255 by 24 places cannot be represented in type 'int'
  at 0x102d47f44 lv_canvas_fill_bg (lv_canvas.c:310)
  at 0x102812b30 canvas_basic_render(unsigned char*, unsigned char, char const*, char const*) (main.cpp:38)
  at 0x102811fd4 canvas_blend_test(_lv_obj_t*, _lv_draw_image_dsc_t*, char const*, char const*, unsigned char, unsigned int) (main.cpp:108)
  at 0x102814f50 canvas_draw(char const*, unsigned char) (main.cpp:154)
  at 0x102814858 test_xrgb8888() (main.cpp:162)
  at 0x10281536c main (main.cpp:218)
  at 0x18d0790dc
```
---
 src/widgets/canvas/lv_canvas.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/widgets/canvas/lv_canvas.c b/src/widgets/canvas/lv_canvas.c
index d16958f32..b5611833e 100644
--- a/src/widgets/canvas/lv_canvas.c
+++ b/src/widgets/canvas/lv_canvas.c
@@ -311,7 +311,7 @@ void lv_canvas_fill_bg(lv_obj_t * obj, lv_color_t color, lv_opa_t opa)
         uint32_t c32 = lv_color_to_u32(color);
         if(header->cf == LV_COLOR_FORMAT_ARGB8888) {
             c32 &= 0x00ffffff;
-            c32 |= opa << 24;
+            c32 |= (uint32_t)opa << 24;
         }
         for(y = 0; y < header->h; y++) {
             uint32_t * buf32 = (uint32_t *)(data + y * stride);