From 5448763b9d9d7795be1d7794c37761712dcf5cb1 Mon Sep 17 00:00:00 2001
From: 0xboobface <0xboobface@gmail.com>
Date: Fri, 3 Jan 2020 21:53:37 +0100
Subject: [PATCH] Fix possible NPE

---
 .../ctbrec/recorder/download/dash/FfmpegMuxer.java   | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/common/src/main/java/ctbrec/recorder/download/dash/FfmpegMuxer.java b/common/src/main/java/ctbrec/recorder/download/dash/FfmpegMuxer.java
index 971b89b6..47723943 100644
--- a/common/src/main/java/ctbrec/recorder/download/dash/FfmpegMuxer.java
+++ b/common/src/main/java/ctbrec/recorder/download/dash/FfmpegMuxer.java
@@ -6,6 +6,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.util.Arrays;
+import java.util.Optional;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -22,9 +23,16 @@ public class FfmpegMuxer {
 
     public FfmpegMuxer(File segmentDir, File targetFile) throws IOException {
         this.segmentDir = segmentDir;
-        String[] videoSegments = segmentDir.list((dir, name) -> name.startsWith("video_"));
+        if (!segmentDir.exists()) {
+            throw new IOException("Directory does not exist " + segmentDir);
+        }
+        if (!segmentDir.isDirectory()) {
+            throw new IOException(segmentDir + " is not a directory");
+        }
+
+        String[] videoSegments = Optional.ofNullable(segmentDir.list((dir, name) -> name.startsWith("video_"))).orElse(new String[0]);
         Arrays.sort(videoSegments);
-        String[] audioSegments = segmentDir.list((dir, name) -> name.startsWith("audio_"));
+        String[] audioSegments = Optional.ofNullable(segmentDir.list((dir, name) -> name.startsWith("audio_"))).orElse(new String[0]);
         Arrays.sort(audioSegments);
 
         File mp4VideoTrack = new File(segmentDir, "video.mp4");