degesch: expand/analyze a few TODO comments

Works for aliases as well.  Resolves a TODO entry.

NEWS

@@ -13,6 +13,8 @@
 
  * degesch: /set +=/-= now treats its argument as a string array
 
+ * degesch: made "/help /command" work the same way as "/help command" does
+
  * censor.lua: now stripping colours from censored messages;
    their attributes are also configurable rather than always black on black
 

degesch.c

@@ -4101,6 +4101,13 @@ buffer_open_log_file (struct app_context *ctx, struct buffer *buffer)
 		return;
 
 	// TODO: should we try to reopen files wrt. case mapping?
+	//  - Need to read the whole directory and look for matches:
+	//    irc_server_strcmp(buffer->s, d_name, make_log_filename())
+	//    remember to strip the ".log" suffix from d_name, case-sensitively.
+	//  - The tolower_ascii() in make_log_filename() is a perfect overlap,
+	//    it may stay as-is.
+	//  - buffer_get_log_path() will need to return a FILE *,
+	//    or an error that includes the below message.
 	char *path = buffer_get_log_path (buffer);
 	if (!(buffer->log_file = fopen (path, "ab")))
 		log_global_error (ctx, "Couldn't open log file `#s': #l",
@@ -8132,8 +8139,8 @@ irc_process_message (const struct irc_message *msg, struct server *s)
 		irc_sanitize_cut_off_utf8 (&msg->params.vector[msg->params.len - 1]);
 
 	// TODO: make use of IRCv3.2 server-time (with fallback to unixtime_msec())
-	//   -> change all calls to log_{server,nick,outcoming,ctcp}*() to take
-	//   an extra argument specifying time
+	//   -> change all calls to log_{server,nick,chghost,outcoming,ctcp}*()
+	//   to take an extra numeric argument specifying time
 	struct irc_handler key = { .name = msg->command };
 	struct irc_handler *handler = bsearch (&key, g_irc_handlers,
 		N_ELEMENTS (g_irc_handlers), sizeof key, irc_handler_cmp_by_name);
@@ -11559,7 +11566,8 @@ handle_command_topic (struct handler_args *a)
 	if (*a->arguments)
 		// FIXME: there's no way to start the topic with whitespace
 		// FIXME: there's no way to unset the topic;
-		//   we could adopt the Tcl style of "-switches" with "--" sentinels
+		//   we could adopt the Tcl style of "-switches" with "--" sentinels,
+		//   or we could accept "strings" in the config format
 		irc_send (a->s, "TOPIC %s :%s", a->channel_name, a->arguments);
 	else
 		irc_send (a->s, "TOPIC %s", a->channel_name);
@@ -11638,7 +11646,9 @@ mass_channel_mode_mask_list
 	for (size_t i = 0; i < v.len; i++)
 	{
 		char *target = v.vector[i];
-		// TODO: support EXTBAN and leave those alone, too
+		// TODO: support EXTBAN=<[PREFIX],TYPES> and leave those alone, too.
+		//   The type may be prefixed by ~, and must be followed by \0 or ':'.
+		//   Make a function like irc_is_extban().
 		if (strpbrk (target, "!@*?"))
 			continue;
 
@@ -12188,8 +12198,9 @@ handle_command_help (struct handler_args *a)
 	if (!*a->arguments)
 		return show_command_list (ctx);
 
-	// TODO: we should probably also accept commands names with a leading slash
-	char *command = cut_word (&a->arguments);
+	const char *word = cut_word (&a->arguments);
+
+	const char *command = word + (*word == '/');
 	for (size_t i = 0; i < N_ELEMENTS (g_command_handlers); i++)
 	{
 		struct command_handler *handler = &g_command_handlers[i];
@@ -12197,13 +12208,13 @@ handle_command_help (struct handler_args *a)
 			return show_command_help (ctx, handler);
 	}
 
-	if (try_handle_command_help_option (ctx, command))
+	if (try_handle_command_help_option (ctx, word))
 		return true;
 
 	if (str_map_find (get_aliases_config (ctx), command))
 		log_global_status (ctx, "/#s is an alias", command);
 	else
-		log_global_error (ctx, "#s: #s", "No such command or option", command);
+		log_global_error (ctx, "#s: #s", "No such command or option", word);
 	return true;
 }
 
@@ -12278,6 +12289,12 @@ expand_alias_escape (const char *p, const char *arguments, struct str *output)
 	cstr_split (arguments, " ", true, &words);
 
 	// TODO: eventually also add support for argument ranges
+	//  - Can use ${0}, ${0:}, ${:0}, ${1:-1} with strtol, dispose of $1 syntax
+	//    (default aliases don't use numeric arguments).
+	//  - Start numbering from zero, since we'd have to figure out what to do
+	//    in case we encounter a zero if we keep the current approach.
+	//  - Ignore the sequence altogether if no closing '}' can be found,
+	//    or if the internal format doesn't fit the above syntax.
 	if (*p >= '1' && *p <= '9')
 	{
 		size_t offset = *p - '1';