From 661e4f1ac28f2878440f544a765e5d1af61462f0 Mon Sep 17 00:00:00 2001
From: Julien Couvreur <jcouv@microsoft.com>
Date: Fri, 20 Jul 2018 08:52:40 -0700
Subject: [PATCH] Address PR feedback (2)

---
 .../Portable/FlowAnalysis/NullableWalker.cs   |  2 +-
 .../Semantics/NullableReferenceTypesTests.cs  | 29 ++++++++++++++-----
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs b/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs
index 03157e5675258..d7636df83da34 100644
--- a/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs
+++ b/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs
@@ -781,7 +781,7 @@ public override BoundNode VisitIsPatternExpression(BoundIsPatternExpression node
         /// `switch (x) ... case Point p:` // PROTOTYPE(NullableReferenceTypes): not yet handled
         ///
         /// If the expression is trackable, we'll return with different null-states for that expression in the two conditional states.
-        /// If the patterns is a `var` pattern, we'll also have re-inferred the `var` type with nullability and
+        /// If the pattern is a `var` pattern, we'll also have re-inferred the `var` type with nullability and
         /// updated the state for that declared local.
         /// </summary>
         private void VisitPattern(BoundExpression expression, TypeSymbolWithAnnotations expressionResultType, BoundPattern pattern)
diff --git a/src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs b/src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs
index bd50cc3e60151..69231be44d1bf 100644
--- a/src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs
+++ b/src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs
@@ -12131,12 +12131,21 @@ void Test(object? x)
     {
         if (x is var c)
         {
-            x.ToString(); // warn
-            c /*T:object?*/ .ToString(); // warn
+            x.ToString(); // warn 1
+            c /*T:object?*/ .ToString(); // warn 2
         }
         else
         {
-            x.ToString(); // warn
+            x.ToString(); // warn 3
+        }
+
+        if (x is var _)
+        {
+            x.ToString(); // warn 4
+        }
+        else
+        {
+            x.ToString(); // warn 5
         }
     }
 }
@@ -12145,14 +12154,20 @@ void Test(object? x)
             c.VerifyTypes();
             c.VerifyDiagnostics(
                 // (8,13): warning CS8602: Possible dereference of a null reference.
-                //             x.ToString(); // warn
+                //             x.ToString(); // warn 1
                 Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "x").WithLocation(8, 13),
                 // (9,13): warning CS8602: Possible dereference of a null reference.
-                //             c /*T:object?*/ .ToString(); // warn
+                //             c /*T:object?*/ .ToString(); // warn 2
                 Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "c").WithLocation(9, 13),
                 // (13,13): warning CS8602: Possible dereference of a null reference.
-                //             x.ToString(); // warn
-                Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "x").WithLocation(13, 13)
+                //             x.ToString(); // warn 3
+                Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "x").WithLocation(13, 13),
+                // (18,13): warning CS8602: Possible dereference of a null reference.
+                //             x.ToString(); // warn 4
+                Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "x").WithLocation(18, 13),
+                // (22,13): warning CS8602: Possible dereference of a null reference.
+                //             x.ToString(); // warn 5
+                Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "x").WithLocation(22, 13)
                 );
         }