From 03f2ff096a5310f985b20624c5de4fb5c4ff119d Mon Sep 17 00:00:00 2001
From: Marcos Henrich <marcos.henrich@xamarin.com>
Date: Mon, 11 Jan 2016 17:54:52 +0000
Subject: [PATCH] [System.Xml] Fix sub class serialization on lists

Fixes failure, where XmlSerializer would crash while serializing
a list with multiple XmlElement when a sub class of the XmlElement is
used.

Fixes #36829.
---
 .../System.XML/System.Xml.Serialization/XmlTypeMapping.cs     | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/mcs/class/System.XML/System.Xml.Serialization/XmlTypeMapping.cs b/mcs/class/System.XML/System.Xml.Serialization/XmlTypeMapping.cs
index aded011e986..f70bd99464b 100644
--- a/mcs/class/System.XML/System.Xml.Serialization/XmlTypeMapping.cs
+++ b/mcs/class/System.XML/System.Xml.Serialization/XmlTypeMapping.cs
@@ -646,8 +646,15 @@ namespace System.Xml.Serialization
 			{
 				if (memberValue == null) return null;
 				Type type = memberValue.GetType();
-				foreach (XmlTypeMapElementInfo elem in _itemInfo)
-					if (elem.TypeData.Type == type) return elem;
+				XmlTypeMapElementInfo bestMatch = null;
+				foreach (XmlTypeMapElementInfo elem in _itemInfo) {
+					if (elem.TypeData.Type == type)
+						return elem;
+					if (elem.TypeData.Type.IsAssignableFrom (type) &&
+						(bestMatch == null || elem.TypeData.Type.IsAssignableFrom (bestMatch.TypeData.Type)))
+						bestMatch = elem;
+				}
+				return bestMatch;
 			}
 			return null;
 		}	
-- 
2.11.4.GIT