fix(checkbox): check for mem allocation failure in set_text (#4089)

src/widgets/checkbox/lv_checkbox.c

@@ -68,14 +68,22 @@ lv_obj_t * lv_checkbox_create(lv_obj_t * parent)
 void lv_checkbox_set_text(lv_obj_t * obj, const char * txt)
 {
     lv_checkbox_t * cb = (lv_checkbox_t *)obj;
+
+    if(NULL != txt) {
+        size_t len = 0;
+
 #if LV_USE_ARABIC_PERSIAN_CHARS
-    size_t len = _lv_txt_ap_calc_bytes_cnt(txt);
+        len = _lv_txt_ap_calc_bytes_cnt(txt);
 #else
-    size_t len = strlen(txt);
+        len = strlen(txt);
 #endif
 
         if(!cb->static_txt) cb->txt = lv_realloc(cb->txt, len + 1);
         else cb->txt = lv_malloc(len + 1);
+
+        LV_ASSERT_MALLOC(cb->txt);
+        if(NULL == cb->txt) return;
+
 #if LV_USE_ARABIC_PERSIAN_CHARS
         _lv_txt_ap_proc(txt, cb->txt);
 #else
@@ -83,6 +91,7 @@ void lv_checkbox_set_text(lv_obj_t * obj, const char * txt)
 #endif
 
         cb->static_txt = 0;
+    }
 
     lv_obj_refresh_self_size(obj);
     lv_obj_invalidate(obj);

tests/src/test_cases/test_checkbox.c

@@ -93,4 +93,42 @@ void test_checkbox_should_allocate_memory_for_static_text(void)
     LV_HEAP_CHECK(TEST_ASSERT_LESS_THAN(initial_available_memory, m1.free_size));
 }
 
+size_t malloc_calls = 0;
+
+void * malloc_stub(size_t size)
+{
+    (void) size;
+    malloc_calls++;
+
+    return NULL;
+}
+
+void test_checkbox_text_should_become_null_when_mem_allocation_fails(void)
+{
+    const char * message = "Hello World!";
+    active_screen = lv_scr_act();
+    checkbox = lv_checkbox_create(active_screen);
+    lv_test_malloc_set_cb(malloc_stub);
+
+    lv_checkbox_set_text(checkbox, message);
+
+    TEST_ASSERT_NULL(lv_checkbox_get_text(checkbox));
+
+    lv_test_malloc_set_cb(NULL);
+}
+
+void test_checkbox_no_memory_allocation_when_refreshing_text(void)
+{
+    malloc_calls = 0;
+    active_screen = lv_scr_act();
+    checkbox = lv_checkbox_create(active_screen);
+    lv_test_malloc_set_cb(malloc_stub);
+
+    lv_checkbox_set_text(checkbox, NULL);
+
+    TEST_ASSERT_EQUAL(0, malloc_calls);
+
+    lv_test_malloc_set_cb(NULL);
+}
+
 #endif