Validate length of configuration names from add*Conf HPM commands

Providing a too long name/path would silently fail otherwise.

src/common/HPM.c

@@ -451,6 +451,11 @@ static bool hplugins_addconf(unsigned int pluginID, enum HPluginConfType type, c
 		return false;
 	}
 
+	if (strnlen(name, HPM_ADDCONF_LENGTH) >= HPM_ADDCONF_LENGTH) {
+		ShowError("HPM->addConf:%s: config '%s' name/path is too long. Maximum is %d characters (see #define HPM_ADDCONF_LENGTH). Skipping it.\n", HPM->pid2name(pluginID), name, HPM_ADDCONF_LENGTH - 1);
+		return false;
+	}
+
 	ARR_FIND(0, VECTOR_LENGTH(HPM->config_listeners[type]), i, strcmpi(name, VECTOR_INDEX(HPM->config_listeners[type], i).key) == 0);
 	if (i != VECTOR_LENGTH(HPM->config_listeners[type])) {
 		ShowError("HPM->addConf:%s: duplicate '%s', already in use by '%s'!",

src/common/HPMi.h

@@ -35,6 +35,8 @@ struct map_session_data;
 struct hplugin_data_store;
 
 #define HPM_VERSION "1.2"
+
+// Maximum length of the configuration path for configs added with add*Conf
 #define HPM_ADDCONF_LENGTH 40
 
 struct hplugin_info {