From 21192c842474c0f45f943bbfdfaa7cfa8fa8a4f1 Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Wed, 21 Jun 2017 12:52:20 +0200
Subject: [PATCH] [mcs] Add missing vector cloning of definite assignment
 on-true. Fixes #57505

---
 mcs/errors/cs0165-57.cs | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
 mcs/errors/cs0165-58.cs | 49 ++++++++++++++++++++++++++++++++++++++++++++
 mcs/mcs/statement.cs    |  5 +++--
 3 files changed, 106 insertions(+), 2 deletions(-)
 create mode 100644 mcs/errors/cs0165-57.cs
 create mode 100644 mcs/errors/cs0165-58.cs

diff --git a/mcs/errors/cs0165-57.cs b/mcs/errors/cs0165-57.cs
new file mode 100644
index 00000000000..61bb2c6b502
--- /dev/null
+++ b/mcs/errors/cs0165-57.cs
@@ -0,0 +1,54 @@
+// CS0165: Use of unassigned local variable `v'
+// Line: 52
+
+struct Vector3
+{
+	int field1, field2, field3;
+}
+
+public class C
+{
+	void Update ()
+	{
+		int v1 = 0;
+		int v2 = 0;
+		int v3 = 0;
+		int v4 = 0;
+		int v5 = 0;
+		int v6 = 0;
+		int v7 = 0;
+		int v8 = 0;
+		int v9 = 0;
+		int v10 = 0;
+		int v11 = 0;
+		int v12 = 0;
+		int v13 = 0;
+		int v14 = 0;
+		int v15 = 0;
+		int v16 = 0;
+		int v17 = 0;
+		int v18 = 0;
+		int v19 = 0;
+		int v20 = 0;
+		int v21 = 0;
+		int v22 = 0;
+		int v23 = 0;
+		int v24 = 0;
+		int v25 = 0;
+		int v26 = 0;
+		int v27 = 0;        
+		int v29;
+
+		Vector3 v;
+		if (v1 == 0)
+		{
+			v = new Vector3 ();
+		}
+		else if (v2 >= 0.5)
+		{
+			v = new Vector3 ();
+		}
+
+		System.GC.KeepAlive (v);
+	}
+}
\ No newline at end of file
diff --git a/mcs/errors/cs0165-58.cs b/mcs/errors/cs0165-58.cs
new file mode 100644
index 00000000000..71b1cc4f01d
--- /dev/null
+++ b/mcs/errors/cs0165-58.cs
@@ -0,0 +1,49 @@
+// CS0165: Use of unassigned local variable `v'
+// Line: 52
+
+struct Vector3
+{
+	int field1, field2, field3;
+}
+
+public class C
+{
+	void Update ()
+	{
+		int v1 = 0;
+		int v2 = 0;
+		int v3 = 0;
+		int v4 = 0;
+		int v5 = 0;
+		int v6 = 0;
+		int v7 = 0;
+		int v8 = 0;
+		int v9 = 0;
+		int v10 = 0;
+		int v11 = 0;
+		int v12 = 0;
+		int v13 = 0;
+		int v14 = 0;
+		int v15 = 0;
+		int v16 = 0;
+		int v17 = 0;
+		int v18 = 0;
+		int v19 = 0;
+		int v20 = 0;
+		int v21 = 0;
+		int v22 = 0;
+		int v23 = 0;
+		int v24 = 0;
+		int v25 = 0;
+		int v26 = 0;
+		int v27 = 0;        
+		int v29;
+
+		Vector3 v;
+		while (v8 != 0) {
+			v = new Vector3 ();
+		}
+
+		System.GC.KeepAlive (v);
+	}
+}
\ No newline at end of file
diff --git a/mcs/mcs/statement.cs b/mcs/mcs/statement.cs
index dd7f737139e..7a379fc172a 100644
--- a/mcs/mcs/statement.cs
+++ b/mcs/mcs/statement.cs
@@ -269,7 +269,7 @@ namespace Mono.CSharp {
 
 			var da_false = new DefiniteAssignmentBitSet (fc.DefiniteAssignmentOnFalse);
 
-			fc.DefiniteAssignment = fc.DefiniteAssignmentOnTrue;
+			fc.BranchDefiniteAssignment (fc.DefiniteAssignmentOnTrue);
 			var labels = fc.CopyLabelStack ();
 
 			var res = TrueStatement.FlowAnalysis (fc);
@@ -578,9 +578,10 @@ namespace Mono.CSharp {
 		{
 			expr.FlowAnalysisConditional (fc);
 
-			fc.DefiniteAssignment = fc.DefiniteAssignmentOnTrue;
 			var da_false = new DefiniteAssignmentBitSet (fc.DefiniteAssignmentOnFalse);
 
+			fc.BranchDefiniteAssignment (fc.DefiniteAssignmentOnTrue);
+
 			Statement.FlowAnalysis (fc);
 
 			//
-- 
2.11.4.GIT