config_options: Handle ACO arrays correctly in generated XML docs.

There are 3 separate changes here but they are all closely related:

* Only try to set matchfield attributes on 'field' nodes

* We need to adjust how we treat the category pointer based on the
  value of the category_match, to avoid memory corruption. We now
  generate a regex-like string when match types other than
  ACO_WHITELIST and ACO_BLACKLIST are used.

* Switch app_agent_pool from ACO_BLACKLIST_ARRAY to
  ACO_BLACKLIST_EXACT since we only have one category we need to
  ignore, not two.

ASTERISK-29614 #close

Change-Id: I7be7bdb1bb9814f942bc6bb4fdd0a55a7b7efe1e

apps/app_agent_pool.c

@@ -456,17 +456,11 @@ struct agents_cfg {
 	struct ao2_container *agents;
 };
 
-static const char *agent_type_blacklist[] = {
-	"general",
-	"agents",
-	NULL,
-};
-
 static struct aco_type agent_type = {
 	.type = ACO_ITEM,
 	.name = "agent-id",
-	.category_match = ACO_BLACKLIST_ARRAY,
-	.category = (const char *)agent_type_blacklist,
+	.category_match = ACO_BLACKLIST_EXACT,
+	.category = "general",
 	.item_alloc = agent_cfg_alloc,
 	.item_find = agent_cfg_find,
 	.item_offset = offsetof(struct agents_cfg, agents),

main/config_options.c

@@ -1037,6 +1037,45 @@ static char *complete_config_option(const char *module, const char *option, cons
 	return NULL;
 }
 
+/*! \internal
+ * \brief Generate a category match string suitable for display in 'config show help'
+ */
+static struct ast_str *derive_category_text(enum aco_category_op category_match, const char *category)
+{
+	struct ast_str *s = ast_str_create(128);
+
+	if (!s) {
+		return NULL;
+	}
+
+	switch (category_match) {
+	case ACO_WHITELIST_ARRAY:
+	case ACO_BLACKLIST_ARRAY: {
+		size_t i;
+		const char **matches = (const char **) category;
+		ast_str_append(&s, 0, "^(");
+		for (i = 0; matches[i]; i++) {
+			ast_str_append(&s, 0, "%s%s",
+				i ? "|" : "",
+				matches[i]);
+		}
+		ast_str_append(&s, 0, ")$");
+		break;
+	}
+	case ACO_WHITELIST_EXACT:
+	case ACO_BLACKLIST_EXACT:
+		ast_str_set(&s, 0, "^%s$", category);
+		break;
+	case ACO_WHITELIST:
+	case ACO_BLACKLIST:
+	default:
+		ast_str_set(&s, 0, "%s", category);
+		break;
+	}
+
+	return s;
+}
+
 /* Define as 0 if we want to allow configurations to be registered without
  * documentation
  */
@@ -1051,6 +1090,7 @@ static int xmldoc_update_config_type(const char *module, const char *name, const
 	RAII_VAR(struct ast_xml_doc_item *, config_info, ao2_find(xmldocs, module, OBJ_KEY), ao2_cleanup);
 	struct ast_xml_doc_item *config_type;
 	struct ast_xml_node *type, *syntax, *matchinfo, *tmp;
+	struct ast_str *derived_category = NULL;
 
 	/* If we already have a syntax element, bail. This isn't an error, since we may unload a module which
 	 * has updated the docs and then load it again. */
@@ -1083,7 +1123,12 @@ static int xmldoc_update_config_type(const char *module, const char *name, const
 		return XMLDOC_STRICT ? -1 : 0;
 	}
 
-	ast_xml_set_text(tmp, category);
+	derived_category = derive_category_text(category_match, category);
+	if (derived_category) {
+		ast_xml_set_text(tmp, ast_str_buffer(derived_category));
+		ast_free(derived_category);
+	}
+
 	switch (category_match) {
 	case ACO_WHITELIST:
 	case ACO_WHITELIST_EXACT:
@@ -1097,14 +1142,15 @@ static int xmldoc_update_config_type(const char *module, const char *name, const
 		break;
 	}
 
-	if (!ast_strlen_zero(matchfield) && !(tmp = ast_xml_new_child(matchinfo, "field"))) {
-		ast_log(LOG_WARNING, "Could not add %s attribute for type '%s' in module '%s'\n", matchfield, name, module);
-		return XMLDOC_STRICT ? -1 : 0;
+	if (!ast_strlen_zero(matchfield)) {
+		if (!(tmp = ast_xml_new_child(matchinfo, "field"))) {
+			ast_log(LOG_WARNING, "Could not add %s attribute for type '%s' in module '%s'\n", matchfield, name, module);
+			return XMLDOC_STRICT ? -1 : 0;
+		}
+		ast_xml_set_attribute(tmp, "name", matchfield);
+		ast_xml_set_text(tmp, matchvalue);
 	}
 
-	ast_xml_set_attribute(tmp, "name", matchfield);
-	ast_xml_set_text(tmp, matchvalue);
-
 	if (!config_info || !(config_type = find_xmldoc_type(config_info, name))) {
 		ast_log(LOG_WARNING, "Could not obtain XML documentation item for config type %s\n", name);
 		return XMLDOC_STRICT ? -1 : 0;