fix(esp_cli_commands): Help not visible when command_set passed to esp_cli

when a command set is used in esp_cli config, the help command is not
shown by the cli if not explicitly mentioned in the command set.
Fix this by making sure help is always made available by esp_cli_commands
APIs

Author: SoucheSouche

esp_cli_commands/idf_component.yml

@@ -1,4 +1,4 @@
-version: "0.1.2"
+version: "0.1.3"
 description: "esp_cli_commands - Command handling component"
 url: https://github.com/espressif/idf-extra-components/tree/master/esp_cli_commands
 dependencies:

esp_cli_commands/src/esp_cli_commands.c

@@ -129,11 +129,11 @@ void go_through_commands(esp_cli_command_sets_t *cmd_sets, void *cmd_walker_ctx,
     }
 
     esp_cli_command_set_t *dynamic_set = cmd_sets ? &cmd_sets->dynamic_set : NULL;
-    /* it is possible that the set is empty, in which case set dynamic_set to NULL
-     * to prevent the for loop to try to access a list of commands pointer set to NULL */
-    if (dynamic_set && !dynamic_set->cmd_ptr_set) {
-        dynamic_set = NULL;
-    }
+    /* Note: unlike FOR_EACH_STATIC_COMMAND which uses the comma operator,
+     * FOR_EACH_DYNAMIC_COMMAND uses && short-circuit evaluation, so it is safe
+     * to pass a set with cmd_ptr_set == NULL and cmd_set_size == 0.
+     * We must NOT null out the set here, because FOR_EACH_DYNAMIC_COMMAND(NULL, ...)
+     * means "walk ALL dynamic commands", bypassing the set filter. */
     esp_cli_dynamic_commands_lock();
     FOR_EACH_DYNAMIC_COMMAND(dynamic_set, cmd) {
         continue_walk = cmd_walker(cmd_walker_ctx, cmd);
@@ -325,6 +325,13 @@ esp_cli_command_t *esp_cli_commands_find_command(esp_cli_command_set_handle_t cm
     find_cmd_ctx_t ctx = { .cmd = NULL, .name = name };
     go_through_commands(cmd_set, &ctx, compare_command_name);
 
+    /* The "help" command is a built-in registered by esp_cli_commands itself.
+     * It must always be found regardless of the command set passed by the user.
+     * If not found in the filtered set, search all commands. */
+    if (!ctx.cmd && cmd_set != NULL && strcmp(name, "help") == 0) {
+        go_through_commands(NULL, &ctx, compare_command_name);
+    }
+
     /* if command was found during the walk, cmd field will be populated with
      * the command matching the name given in parameter, otherwise it will still
      * be NULL (value set as default value above) */
@@ -541,6 +548,12 @@ void esp_cli_commands_get_completion(esp_cli_command_set_handle_t cmd_set, const
         .completion_cb = completion_cb
     };
     go_through_commands(cmd_set, &ctx, call_completion_cb);
+
+    /* The "help" command is a built-in that must always be completable
+     * regardless of the command set */
+    if (cmd_set != NULL && len <= 4 && strncmp(buf, "help", len) == 0) {
+        completion_cb(cb_ctx, "help");
+    }
 }
 
 const char *esp_cli_commands_get_hint(esp_cli_command_set_handle_t cmd_set, const char *buf, int *color, bool *bold)
@@ -740,6 +753,22 @@ static int help_command(void *context, esp_cli_commands_exec_arg_t *cmd_args, in
     };
     go_through_commands(cmd_sets, &ctx, call_command_funcs);
 
+    /* The "help" command is a built-in that must always appear in listings
+     * regardless of the command set */
+    if (cmd_sets != NULL) {
+        esp_cli_command_t *help_cmd = esp_cli_commands_find_command(NULL, "help");
+        if (help_cmd) {
+            if (!command_name) {
+                /* Listing all commands: also print the help entry */
+                print_verbose_level_arr[verbose_level](cmd_args, help_cmd);
+            } else if (strcmp(command_name, "help") == 0) {
+                /* User asked specifically for "help help" */
+                print_verbose_level_arr[verbose_level](cmd_args, help_cmd);
+                ctx.command_found = true;
+            }
+        }
+    }
+
     if (command_name && !ctx.command_found) {
         ESP_CLI_COMMANDS_FD_PRINT(cmd_args->out_fd, cmd_args->write_func, "help: invalid command name %s\n", command_name);
         return 1;