Demo: Fixed truncation warning. (#7857)

imgui_demo.cpp

@@ -310,23 +310,24 @@ static ExampleTreeNode* ExampleTree_CreateNode(const char* name, int uid, Exampl
 static ExampleTreeNode* ExampleTree_CreateDemoTree()
 {
     static const char* root_names[] = { "Apple", "Banana", "Cherry", "Kiwi", "Mango", "Orange", "Pear", "Pineapple", "Strawberry", "Watermelon" };
-    char name_buf[32];
+    const size_t NAME_MAX_LEN = sizeof(ExampleTreeNode::Name);
+    char name_buf[NAME_MAX_LEN];
     int uid = 0;
     ExampleTreeNode* node_L0 = ExampleTree_CreateNode("<ROOT>", ++uid, NULL);
     const int root_items_multiplier = 2;
     for (int idx_L0 = 0; idx_L0 < IM_ARRAYSIZE(root_names) * root_items_multiplier; idx_L0++)
     {
-        snprintf(name_buf, 32, "%s %d", root_names[idx_L0 / root_items_multiplier], idx_L0 % root_items_multiplier);
+        snprintf(name_buf, IM_ARRAYSIZE(name_buf), "%s %d", root_names[idx_L0 / root_items_multiplier], idx_L0 % root_items_multiplier);
         ExampleTreeNode* node_L1 = ExampleTree_CreateNode(name_buf, ++uid, node_L0);
         const int number_of_childs = (int)strlen(node_L1->Name);
         for (int idx_L1 = 0; idx_L1 < number_of_childs; idx_L1++)
         {
-            snprintf(name_buf, 32, "Child %d", idx_L1);
+            snprintf(name_buf, IM_ARRAYSIZE(name_buf), "Child %d", idx_L1);
             ExampleTreeNode* node_L2 = ExampleTree_CreateNode(name_buf, ++uid, node_L1);
             node_L2->HasData = true;
             if (idx_L1 == 0)
             {
-                snprintf(name_buf, 32, "Sub-child %d", 0);
+                snprintf(name_buf, IM_ARRAYSIZE(name_buf), "Sub-child %d", 0);
                 ExampleTreeNode* node_L3 = ExampleTree_CreateNode(name_buf, ++uid, node_L2);
                 node_L3->HasData = true;
             }