From 8abcfa68f609e3df59f3be95bb54490b4884409e Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Tue, 4 Aug 2015 15:26:50 +0200
Subject: [PATCH] [mcs] Cached labels definite assignment check does not need
 exact match but anything larger than original set satisfies the condition.
 Fixes #32732

---
 mcs/mcs/context.cs      |  2 +-
 mcs/mcs/flowanalysis.cs | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/mcs/mcs/context.cs b/mcs/mcs/context.cs
index 88e52370070..fbb21d0096f 100644
--- a/mcs/mcs/context.cs
+++ b/mcs/mcs/context.cs
@@ -497,7 +497,7 @@ namespace Mono.CSharp
 			}
 
 			foreach (var existing in das) {
-				if (DefiniteAssignmentBitSet.AreEqual (existing, DefiniteAssignment))
+				if (DefiniteAssignmentBitSet.IsIncluded (existing, DefiniteAssignment))
 					return true;
 			}
 
diff --git a/mcs/mcs/flowanalysis.cs b/mcs/mcs/flowanalysis.cs
index b9189c1f3d6..267879c043b 100644
--- a/mcs/mcs/flowanalysis.cs
+++ b/mcs/mcs/flowanalysis.cs
@@ -552,7 +552,7 @@ namespace Mono.CSharp
 
 		public static DefiniteAssignmentBitSet operator & (DefiniteAssignmentBitSet a, DefiniteAssignmentBitSet b)
 		{
-			if (AreEqual (a, b))
+			if (IsEqual (a, b))
 				return a;
 
 			DefiniteAssignmentBitSet res;
@@ -575,7 +575,7 @@ namespace Mono.CSharp
 
 		public static DefiniteAssignmentBitSet operator | (DefiniteAssignmentBitSet a, DefiniteAssignmentBitSet b)
 		{
-			if (AreEqual (a, b))
+			if (IsEqual (a, b))
 				return a;
 
 			DefiniteAssignmentBitSet res;
@@ -678,7 +678,7 @@ namespace Mono.CSharp
 				large_bits[index >> 5] |= (1 << (index & 31));
 		}
 
-		public static bool AreEqual (DefiniteAssignmentBitSet a, DefiniteAssignmentBitSet b)
+		static bool IsEqual (DefiniteAssignmentBitSet a, DefiniteAssignmentBitSet b)
 		{
 			if (a.large_bits == null)
 				return (a.bits & ~copy_on_write_flag) == (b.bits & ~copy_on_write_flag);
@@ -690,5 +690,20 @@ namespace Mono.CSharp
 
 			return true;
 		}
+
+		public static bool IsIncluded (DefiniteAssignmentBitSet set, DefiniteAssignmentBitSet test)
+		{
+			var set_bits = set.large_bits;
+			if (set_bits == null)
+				return (set.bits & test.bits & ~copy_on_write_flag) == (set.bits & ~copy_on_write_flag);
+
+			var test_bits = test.large_bits;
+			for (int i = 0; i < set_bits.Length; ++i) {
+				if ((set_bits[i] & test_bits[i]) != set_bits[i])
+					return false;
+			}
+
+			return true;
+		}
 	}
 }
-- 
2.11.4.GIT