From d0603fde881242877ee1379a573083e2483092a6 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Fri, 25 Apr 2014 08:54:16 -0700
Subject: [PATCH] Don't check for used extradata ids if there are none

---
 src/ass_file.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ass_file.cpp b/src/ass_file.cpp
index 9d07b6220..2e6a8b712 100644
--- a/src/ass_file.cpp
+++ b/src/ass_file.cpp
@@ -259,9 +259,9 @@ void AssFile::CleanExtradata() {
 	// Then remove all IDs found to be in use from this list
 	// Remaining is then all garbage IDs
 	std::vector<uint32_t> ids;
-	for (auto& it : Extradata) {
+	for (auto& it : Extradata)
 		ids.push_back(it.first);
-	}
+	if (ids.empty()) return;
 
 	// For each line, find which IDs it actually uses and remove them from the unused-list
 	for (auto& line : Events) {