Work toward being able to back-target to v3.5.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/DotNetOpenAuth/Messaging/MessagingUtilities.cs b/src/DotNetOpenAuth/Messaging/MessagingUtilities.cs
index 3764c2f..be5927f 100644
--- a/src/DotNetOpenAuth/Messaging/MessagingUtilities.cs
+++ b/src/DotNetOpenAuth/Messaging/MessagingUtilities.cs
@@ -316,6 +316,26 @@ namespace DotNetOpenAuth.Messaging {
 			}
 		}
 
+#if !CLR4
+		/// <summary>
+		/// Copies the contents of one stream to another.
+		/// </summary>
+		/// <param name="copyFrom">The stream to copy from, at the position where copying should begin.</param>
+		/// <param name="copyTo">The stream to copy to, at the position where bytes should be written.</param>
+		/// <returns>The total number of bytes copied.</returns>
+		/// <remarks>
+		/// Copying begins at the streams' current positions.
+		/// The positions are NOT reset after copying is complete.
+		/// </remarks>
+		internal static int CopyTo(this Stream copyFrom, Stream copyTo) {
+			Contract.Requires<ArgumentNullException>(copyFrom != null);
+			Contract.Requires<ArgumentNullException>(copyTo != null);
+			Contract.Requires<ArgumentException>(copyFrom.CanRead, MessagingStrings.StreamUnreadable);
+			Contract.Requires<ArgumentException>(copyTo.CanWrite, MessagingStrings.StreamUnwritable);
+			return CopyUpTo(copyFrom, copyTo, int.MaxValue);
+		}
+#endif
+
 		/// <summary>
 		/// Copies the contents of one stream to another.
 		/// </summary>