From 511a769fdd686ea820b6d2ececc5074e7f1db62f Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Thu, 24 Aug 2017 10:37:05 +0200
Subject: [PATCH] [mcs] Update logic when checking for tuple element names when
 overriding inherited member

---
 mcs/mcs/tuples.cs            |  8 ++++----
 mcs/tests/test-tuple-06.cs   | 19 +++++++++++++++++++
 mcs/tests/ver-il-net_4_x.xml | 21 +++++++++++++++++++++
 3 files changed, 44 insertions(+), 4 deletions(-)
 create mode 100644 mcs/tests/test-tuple-06.cs

diff --git a/mcs/mcs/tuples.cs b/mcs/mcs/tuples.cs
index 559c2f3ee43..bb7faf734df 100644
--- a/mcs/mcs/tuples.cs
+++ b/mcs/mcs/tuples.cs
@@ -234,15 +234,15 @@ namespace Mono.CSharp
 		public static bool CheckOverrideName (TypeSpec type, TypeSpec baseType)
 		{
 			var btype_ntuple = baseType as NamedTupleSpec;
-			var mtype_ntupe = type as NamedTupleSpec;
-			if (btype_ntuple == null && mtype_ntupe == null)
+			var mtype_ntuple = type as NamedTupleSpec;
+			if (btype_ntuple == null && mtype_ntuple == null)
 				return true;
 
-			if (btype_ntuple != null || mtype_ntupe != null)
+			if (btype_ntuple == null || mtype_ntuple == null)
 				return false;
 
 			var b_elements = btype_ntuple.elements;
-			var m_elements = mtype_ntupe.elements;
+			var m_elements = mtype_ntuple.elements;
 			for (int i = 0; i < b_elements.Count; ++i) {
 				if (b_elements [i] != m_elements [i])
 					return false;
diff --git a/mcs/tests/test-tuple-06.cs b/mcs/tests/test-tuple-06.cs
new file mode 100644
index 00000000000..64bb9b05822
--- /dev/null
+++ b/mcs/tests/test-tuple-06.cs
@@ -0,0 +1,19 @@
+class Base
+{
+	public virtual (int, long rest) Foo ()
+	{
+		return (1, 2);
+	}
+}
+
+class Test : Base
+{
+	public override (int, long rest) Foo ()
+	{
+		return (3, 4);
+	}
+
+	public static void Main ()
+	{	
+	}
+}
\ No newline at end of file
diff --git a/mcs/tests/ver-il-net_4_x.xml b/mcs/tests/ver-il-net_4_x.xml
index d3c5c4ff729..db5bfbd387c 100644
--- a/mcs/tests/ver-il-net_4_x.xml
+++ b/mcs/tests/ver-il-net_4_x.xml
@@ -73115,6 +73115,27 @@
       </method>
     </type>
   </test>
+  <test name="test-tuple-06.cs">
+    <type name="Base">
+      <method name="System.ValueTuple`2[System.Int32,System.Int64] Foo()" attrs="454">
+        <size>17</size>
+      </method>
+      <method name="Void .ctor()" attrs="6278">
+        <size>7</size>
+      </method>
+    </type>
+    <type name="Test">
+      <method name="System.ValueTuple`2[System.Int32,System.Int64] Foo()" attrs="198">
+        <size>17</size>
+      </method>
+      <method name="Void Main()" attrs="150">
+        <size>2</size>
+      </method>
+      <method name="Void .ctor()" attrs="6278">
+        <size>7</size>
+      </method>
+    </type>
+  </test>
   <test name="test-var-01.cs">
     <type name="Test">
       <method name="Int32 Main()" attrs="150">
-- 
2.25.1