From b76184325d02c0ceb6b166d77bc04664cdc35c6b Mon Sep 17 00:00:00 2001
From: Jeremy Powell <jeremy@visionaid.com>
Date: Thu, 10 Oct 2024 11:39:00 +1300
Subject: [PATCH] Truncate StreamDecorator reads

Fixes: #184
---
 sources/OpenMcdf.Extensions/StreamDecorator.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sources/OpenMcdf.Extensions/StreamDecorator.cs b/sources/OpenMcdf.Extensions/StreamDecorator.cs
index ee3b04a1..b79202b8 100644
--- a/sources/OpenMcdf.Extensions/StreamDecorator.cs
+++ b/sources/OpenMcdf.Extensions/StreamDecorator.cs
@@ -66,6 +66,11 @@ public override int Read(byte[] buffer, int offset, int count)
             if (position >= cfStream.Size)
                 return 0;
 
+            int maxReadableLength = (int)Math.Min(int.MaxValue, Length - Position);
+            count = Math.Max(0, Math.Min(maxReadableLength, count));
+            if (count == 0)
+                return 0;
+
             count = cfStream.Read(buffer, position, offset, count);
             position += count;
             return count;