From 700b66ffb0de10c3ec0c62c13cc0882cfdac2f10 Mon Sep 17 00:00:00 2001
From: Adam Hathcock <adam.hathcock@autodesk.com>
Date: Wed, 27 May 2015 15:37:54 +0100
Subject: [PATCH] Only use underlying stream when buffered.  Otherwise, it's
 not seekable.

---
 src/Nancy.Tests/Unit/IO/RequestStreamFixture.cs | 15 +++++++++++++++
 src/Nancy/IO/RequestStream.cs                   | 17 ++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/Nancy.Tests/Unit/IO/RequestStreamFixture.cs b/src/Nancy.Tests/Unit/IO/RequestStreamFixture.cs
index 1609121374..ea8662fdba 100644
--- a/src/Nancy.Tests/Unit/IO/RequestStreamFixture.cs
+++ b/src/Nancy.Tests/Unit/IO/RequestStreamFixture.cs
@@ -150,6 +150,21 @@ public void Should_return_false_when_queried_about_supporting_seeking()
             result.ShouldBeFalse();
         }
 
+        [Fact]
+        public void Should_return_true_when_queried_about_supporting_seeking_if_buffered()
+        {
+            // Given
+            var stream = new ConfigurableMemoryStream();
+            var request = RequestStream.FromStream(stream, 0, 1, false);
+            request.BufferStream();
+
+            // When
+            var result = request.CanSeek;
+
+            // Then
+            result.ShouldBeTrue();
+        }
+
         [Fact]
         public void Should_return_underlaying_stream_when_queried_about_supporting_timeout()
         {
diff --git a/src/Nancy/IO/RequestStream.cs b/src/Nancy/IO/RequestStream.cs
index 607c0be8e7..9822a22983 100644
--- a/src/Nancy/IO/RequestStream.cs
+++ b/src/Nancy/IO/RequestStream.cs
@@ -126,7 +126,14 @@ public override bool CanRead
         /// <returns>Returns depending on whether the stream is buffered or not.</returns>
         public override bool CanSeek
         {
-            get { return this.stream.CanSeek; }
+            get
+            {
+                if (!isBuffered)
+                {
+                    return false;
+                }
+                return this.stream.CanSeek;
+            }
         }
 
         /// <summary>
@@ -312,6 +319,10 @@ public override int ReadByte()
         /// <param name="origin">A value of type <see cref="T:System.IO.SeekOrigin"/> indicating the reference point used to obtain the new position. </param>
         public override long Seek(long offset, SeekOrigin origin)
         {
+            if (!isBuffered)
+            {
+                throw new NotSupportedException();
+            }
             return this.stream.Seek(offset, origin);
         }
 
@@ -323,6 +334,10 @@ public override long Seek(long offset, SeekOrigin origin)
         /// <remarks>This functionality is not supported by the <see cref="RequestStream"/> type and will always throw <see cref="NotSupportedException"/>.</remarks>
         public override void SetLength(long value)
         {
+            if (!isBuffered)
+            {
+                throw new NotSupportedException();
+            }
             this.stream.SetLength(value);
         }