Fix order of capturing of this inside switch statement. Fixes #12544

4 files changed, 120 insertions, 12 deletions

diff --git a/mcs/mcs/statement.cs b/mcs/mcs/statement.cs
index ab0b2d7bbd3..b36393fa161 100644
--- a/mcs/mcs/statement.cs
+++ b/mcs/mcs/statement.cs
@@ -2243,6 +2243,11 @@ namespace Mono.CSharp {
 				scope_initializers.Add (s);
 			}
 		}
+
+		public void InsertStatement (int index, Statement s)
+		{
+			statements.Insert (index, s);
+		}
 		
 		public void AddStatement (Statement s)
 		{
@@ -4185,10 +4190,10 @@ namespace Mono.CSharp {
 			}
 
 			//
-			// Needed to emit anonymous storey initialization before
+			// Anonymous storey initialization has to happen before
 			// any generated switch dispatch
 			//
-			block.AddScopeStatement (new DispatchStatement (this));
+			block.InsertStatement (0, new DispatchStatement (this));
 
 			return true;
 		}
@@ -4415,12 +4420,6 @@ namespace Mono.CSharp {
 				return;
 			}
 
-			//
-			// Mark sequence point explicitly to switch
-			//
-			ec.Mark (block.StartLocation);
-			block.IsCompilerGenerated = true;
-
 			if (string_dictionary != null) {
 				DoEmitStringSwitch (ec);
 			} else if (case_labels.Count < 4 || string_labels != null) {
@@ -4456,6 +4455,14 @@ namespace Mono.CSharp {
 				} else if (new_expr != value) {
 					value.EmitAssign (ec, new_expr, false, false);
 				}
+
+
+				//
+				// Next statement is compiler generated we don't need extra
+				// nop when we can use the statement for sequence point
+				//
+				ec.Mark (block.StartLocation);
+				block.IsCompilerGenerated = true;
 			}
 
 			block.Emit (ec);
diff --git a/mcs/tests/test-anon-171.cs b/mcs/tests/test-anon-171.cs
new file mode 100644
index 00000000000..ff084d41e8d
--- /dev/null
+++ b/mcs/tests/test-anon-171.cs
@@ -0,0 +1,52 @@
+using System;
+
+namespace TestAnonSwitch
+{
+	public class MyClass
+	{
+		public event EventHandler<EventArgs> FirstEvent;
+		public event EventHandler<EventArgs> SecondEvent;
+
+		public void Trigger ()
+		{
+			if (FirstEvent != null)
+				FirstEvent (this, EventArgs.Empty);
+		}
+	}
+
+	public class Tester
+	{
+		MyClass myobj;
+
+		public void Test ()
+		{
+			myobj = new MyClass ();
+			var something = "key";
+
+			switch (something) {
+			case "key":
+				myobj.FirstEvent += (sender, e) => {
+					Console.WriteLine ("FirstEvent: {0}", myobj);
+				};
+				break;
+			case "somethingelse":
+				bool? woot = null;
+				myobj.SecondEvent += (sender, e) => {
+					Console.WriteLine ("woot {0}", woot);
+				};
+				break;
+			}
+
+			myobj.Trigger ();
+		}
+	}
+
+	class MainClass
+	{
+		public static void Main ()
+		{
+			var tester = new Tester ();
+			tester.Test ();
+		}
+	}
+}
diff --git a/mcs/tests/test-debug-11-ref.xml b/mcs/tests/test-debug-11-ref.xml
index 5d0b5d1f216..e524e16c296 100644
--- a/mcs/tests/test-debug-11-ref.xml
+++ b/mcs/tests/test-debug-11-ref.xml
@@ -142,7 +142,7 @@
       </sequencepoints>
       <locals />
       <scopes>
-        <entry index="0" start="0x22" end="0x3c" />
+        <entry index="0" start="0x1" end="0x3c" />
         <entry index="1" start="0x28" end="0x2d" />
       </scopes>
     </method>
@@ -159,7 +159,7 @@
       </sequencepoints>
       <locals />
       <scopes>
-        <entry index="0" start="0x28" end="0x38" />
+        <entry index="0" start="0x15" end="0x38" />
         <entry index="1" start="0x2e" end="0x33" />
       </scopes>
     </method>
@@ -178,7 +178,7 @@
       </sequencepoints>
       <locals />
       <scopes>
-        <entry index="0" start="0xb3" end="0xd2" />
+        <entry index="0" start="0x1" end="0xd2" />
         <entry index="1" start="0xb9" end="0xbe" />
       </scopes>
     </method>
@@ -193,7 +193,7 @@
       </sequencepoints>
       <locals />
       <scopes>
-        <entry index="0" start="0x2c" end="0x3b" />
+        <entry index="0" start="0x1" end="0x3b" />
       </scopes>
     </method>
     <method token="0x600000f">
diff --git a/mcs/tests/ver-il-net_4_5.xml b/mcs/tests/ver-il-net_4_5.xml
index ab87701f657..fbbd9fa1239 100644
--- a/mcs/tests/ver-il-net_4_5.xml
+++ b/mcs/tests/ver-il-net_4_5.xml
@@ -51373,6 +51373,55 @@
       </method>

     </type>

   </test>

+  <test name="test-anon-171.cs">

+    <type name="TestAnonSwitch.MyClass">

+      <method name="Void add_FirstEvent(System.EventHandler`1[System.EventArgs])" attrs="2182">

+        <size>42</size>

+      </method>

+      <method name="Void remove_FirstEvent(System.EventHandler`1[System.EventArgs])" attrs="2182">

+        <size>42</size>

+      </method>

+      <method name="Void add_SecondEvent(System.EventHandler`1[System.EventArgs])" attrs="2182">

+        <size>42</size>

+      </method>

+      <method name="Void remove_SecondEvent(System.EventHandler`1[System.EventArgs])" attrs="2182">

+        <size>42</size>

+      </method>

+      <method name="Void Trigger()" attrs="134">

+        <size>30</size>

+      </method>

+      <method name="Void .ctor()" attrs="6278">

+        <size>7</size>

+      </method>

+    </type>

+    <type name="TestAnonSwitch.Tester">

+      <method name="Void Test()" attrs="134">

+        <size>157</size>

+      </method>

+      <method name="Void .ctor()" attrs="6278">

+        <size>7</size>

+      </method>

+    </type>

+    <type name="TestAnonSwitch.MainClass">

+      <method name="Void Main()" attrs="150">

+        <size>14</size>

+      </method>

+      <method name="Void .ctor()" attrs="6278">

+        <size>7</size>

+      </method>

+    </type>

+    <type name="TestAnonSwitch.Tester+&lt;Test&gt;c__AnonStorey0">

+      <method name="Void &lt;&gt;m__0(System.Object, System.EventArgs)" attrs="131">

+        <size>23</size>

+      </method>

+      <method name="Void &lt;&gt;m__1(System.Object, System.EventArgs)" attrs="131">

+        <size>23</size>

+      </method>

+      <method name="Void .ctor()" attrs="6278">

+        <size>7</size>

+      </method>

+    </type>

+  </test>

   <test name="test-anon-18.cs">

     <type name="A">

       <method name="Void Invoke()" attrs="454">