[ESP-WIFI-MESH] esp_mesh_delete_group_id() not working correctly, with pandora condition (IDFGH-13893)

[mmrein]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

ESP-IDF: tested on v4.4.6 and v5.3.1

Expected behavior:

Delete number of addresses matching those provided by pointer, leaving other addresses intact.

Actual behavior:

Selected address is deleted, but resulting list of addresses after deletion is incorrect. Repeated address adding and deleting results in pandora situation.

Steps to reproduce:

1. Get some example where esp-wifi-mesh is used and initialized, for example: https://github.com/espressif/esp-idf/tree/v5.3.1/examples/mesh/internal_communication
2. Add following code to the end of main (after all init is done)
3. Flash to device and see log output

// XXX Debug test group addr
    int addrCount = 0;
    mesh_addr_t *group_list = NULL;
    esp_err_t ret = ESP_FAIL;

// Initialize and set the list of 3 group addresses
    uint8_t group_ids[3][6] = {{0x01, 0x00, 0x5e, 0x00, 0x00, 0x01}, {0x01, 0x00, 0x5e, 0x00, 0x00, 0x02}, {0x01, 0x00, 0x5e, 0x00, 0x00, 0x03}};
    esp_mesh_set_group_id((mesh_addr_t *)group_ids, 3);
// Check current list
    addrCount = esp_mesh_get_group_num();
    ESP_LOGI(MESH_TAG, "Group addresses count: %i", addrCount);
    // Print addresses
    group_list = heap_caps_malloc(sizeof(mesh_addr_t) * addrCount, MALLOC_CAP_8BIT);
    esp_mesh_get_group_list((mesh_addr_t*)group_list, addrCount);
    for(int i=0; i<addrCount; i++) {
    	ESP_LOGI(MESH_TAG, "Group address %i: " MACSTR, i, MAC2STR((uint8_t*)&group_list[i]));
    }
    free(group_list);

// Delete last address
    ret = esp_mesh_delete_group_id((const mesh_addr_t*)group_ids[2], 1);
    ESP_LOGI(MESH_TAG, "Delete last address: %s", esp_err_to_name(ret));
// Check current list
    addrCount = esp_mesh_get_group_num();
    ESP_LOGI(MESH_TAG, "Group addresses count: %i", addrCount);
    // Print addresses
    group_list = heap_caps_malloc(sizeof(mesh_addr_t) * addrCount, MALLOC_CAP_8BIT);
    esp_mesh_get_group_list((mesh_addr_t*)group_list, addrCount);
    for(int i=0; i<addrCount; i++) {
    	ESP_LOGI(MESH_TAG, "Group address %i: " MACSTR, i, MAC2STR((uint8_t*)&group_list[i]));
    }
    free(group_list);

// Add third address again
    ret = esp_mesh_set_group_id((mesh_addr_t *)group_ids[2], 1);
    ESP_LOGI(MESH_TAG, "Add third address again: %s", esp_err_to_name(ret));
// Check current list
    addrCount = esp_mesh_get_group_num();
    ESP_LOGI(MESH_TAG, "Group addresses count: %i", addrCount);
    // Print addresses
    group_list = heap_caps_malloc(sizeof(mesh_addr_t) * addrCount, MALLOC_CAP_8BIT);
    esp_mesh_get_group_list((mesh_addr_t*)group_list, addrCount);
    for(int i=0; i<addrCount; i++) {
    	ESP_LOGI(MESH_TAG, "Group address %i: " MACSTR, i, MAC2STR((uint8_t*)&group_list[i]));
    }
    free(group_list);

// Delete last address again to find pandora
    ret = esp_mesh_delete_group_id((const mesh_addr_t*)group_ids[2], 1);
    ESP_LOGI(MESH_TAG, "Delete last address again: %s", esp_err_to_name(ret));
// Check current list
    addrCount = esp_mesh_get_group_num();
    ESP_LOGI(MESH_TAG, "Group addresses count: %i", addrCount);
    // Print addresses
    group_list = heap_caps_malloc(sizeof(mesh_addr_t) * addrCount, MALLOC_CAP_8BIT);
    esp_mesh_get_group_list((mesh_addr_t*)group_list, addrCount);
    for(int i=0; i<addrCount; i++) {
    	ESP_LOGI(MESH_TAG, "Group address %i: " MACSTR, i, MAC2STR((uint8_t*)&group_list[i]));
    }
    free(group_list);

Expected Log output:

I (2564) mesh_main: Group addresses count: 3 
I (2564) mesh_main: Group address 0: 01:00:5e:00:00:01 
I (2564) mesh_main: Group address 1: 01:00:5e:00:00:02 
I (2574) mesh_main: Group address 2: 01:00:5e:00:00:03 
I (2574) mesh_main: Delete last address: ESP_OK 
I (2584) mesh_main: Group addresses count: 2 
I (2584) mesh_main: Group address 0: 01:00:5e:00:00:01
I (2594) mesh_main: Group address 1: 01:00:5e:00:00:02 
I (2604) mesh_main: Add third address again: ESP_OK 
I (2604) mesh_main: Group addresses count: 3 
I (2614) mesh_main: Group address 0: 01:00:5e:00:00:01
I (2614) mesh_main: Group address 1: 01:00:5e:00:00:02 
I (2624) mesh_main: Group address 2: 01:00:5e:00:00:03 
I (2634) mesh_main: Delete last address again: ESP_OK 
I (2634) mesh_main: Group addresses count: 2 
I (2614) mesh_main: Group address 0: 01:00:5e:00:00:01
I (2614) mesh_main: Group address 1: 01:00:5e:00:00:02 

Actual Log output:

I (2564) mesh_main: Group addresses count: 3 
I (2564) mesh_main: Group address 0: 01:00:5e:00:00:01 
I (2564) mesh_main: Group address 1: 01:00:5e:00:00:02 
I (2574) mesh_main: Group address 2: 01:00:5e:00:00:03 
I (2574) mesh_main: Delete last address: ESP_OK 
I (2584) mesh_main: Group addresses count: 2 
I (2584) mesh_main: Group address 0: 01:00:5e:00:00:02 
I (2594) mesh_main: Group address 1: 00:00:00:00:00:00 
I (2604) mesh_main: Add third address again: ESP_OK 
I (2604) mesh_main: Group addresses count: 3 
I (2614) mesh_main: Group address 0: 01:00:5e:00:00:02 
I (2614) mesh_main: Group address 1: 00:00:00:00:00:00 
I (2624) mesh_main: Group address 2: 01:00:5e:00:00:03 
E (2624) mesh: [mesh.c,2685] pandora 

I (2634) mesh_main: Delete last address again: ESP_OK 
I (2634) mesh_main: Group addresses count: 2 
I (2644) mesh_main: Group address 0: 01:00:5e:00:00:02 
I (2644) mesh_main: Group address 1: 00:00:00:00:00:00 

Edit: also added an example of adding the address back after deletion and how to find pandora.