From b296c28fde45681b058eb320a3c4e1166420a95b Mon Sep 17 00:00:00 2001
From: Natalia Portillo <claunia@claunia.com>
Date: Fri, 23 Oct 2020 03:25:32 +0100
Subject: [PATCH] Fix XZ crashing filter when file is too small.

---
 Aaru.Filters/XZ.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Aaru.Filters/XZ.cs b/Aaru.Filters/XZ.cs
index 722820c66..fd90c1fc5 100644
--- a/Aaru.Filters/XZ.cs
+++ b/Aaru.Filters/XZ.cs
@@ -79,6 +79,9 @@ namespace Aaru.Filters
             byte[] buffer = new byte[6];
             byte[] footer = new byte[2];
 
+            if(stream.Length < 8)
+                return false;
+
             stream.Seek(0, SeekOrigin.Begin);
             stream.Read(buffer, 0, 6);
             stream.Seek(-2, SeekOrigin.End);
@@ -98,9 +101,11 @@ namespace Aaru.Filters
             byte[] buffer = new byte[6];
             byte[] footer = new byte[2];
 
+            if(stream.Length < 8)
+                return false;
+
             stream.Seek(0, SeekOrigin.Begin);
             stream.Read(buffer, 0, 6);
-            stream.Seek(0, SeekOrigin.Begin);
             stream.Seek(-2, SeekOrigin.End);
             stream.Read(footer, 0, 2);
             stream.Seek(0, SeekOrigin.Begin);