Merge branch 'fixupTests' into parserDiagnostics39

src/Compilers/CSharp/Portable/FlowAnalysis/VariablesDeclaredWalker.cs

@@ -131,12 +131,11 @@ public override void VisitForEachIterationVariables(BoundForEachStatement node)
 
                 if (deconstructionAssignment == null)
                 {
-                    // regular, not deconstructing, foreach declares exactly one iteration variable
-                    _variablesDeclared.Add(node.IterationVariables.Single());
+                    _variablesDeclared.AddAll(node.IterationVariables);
                 }
                 else
                 {
-                    // deconstruction foreach declares multiple variables
+                    // Deconstruction foreach declares multiple variables.
                     ((BoundTupleExpression)deconstructionAssignment.Left).VisitAllElements((x, self) => self.Visit(x), this);
                 }
             }

src/Compilers/CSharp/Test/Semantic/FlowAnalysis/RegionAnalysisTests.cs

@@ -3756,6 +3756,27 @@ void M(ref sbyte p1, ref sbyte? p2)
             Assert.Equal("this, p1, p2, local_0, non_nullable", GetSymbolNamesJoined(dataFlowAnalysisResults.WrittenOutside));
         }
 
+
+        [WorkItem(17971, "https://github.com/dotnet/roslyn/issues/17971")]
+        [Fact]
+        public void VariablesDeclaredInBrokenForeach()
+        {
+            var dataFlowAnalysisResults = CompileAndAnalyzeDataFlowStatements(@"
+struct S
+{
+    static void Main(string[] args)
+    {
+/*<bind>*/
+        Console.WriteLine(1);
+        foreach ()
+        Console.WriteLine(2);
+/*</bind>*/
+    }
+}
+");
+            Assert.Equal(null, GetSymbolNamesJoined(dataFlowAnalysisResults.VariablesDeclared));
+        }
+
         #endregion
 
         #region "lambda"

src/Compilers/CSharp/Test/Symbol/Symbols/SymbolErrorTests.cs

@@ -4066,7 +4066,7 @@ public class Test
             // TODO...
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/18800")]
         public void CS0306ERR_BadTypeArgument01()
         {
             var source =

src/EditorFeatures/CSharpTest/ExtractMethod/ExtractMethodTests.LanguageInteraction.cs

@@ -1930,5 +1930,44 @@ private static FormattableString NewMethod()
 
             await TestExtractMethodAsync(code, expected);
         }
+
+        [WorkItem(17971, "https://github.com/dotnet/roslyn/issues/17971")]
+        [Fact, Trait(Traits.Feature, Traits.Features.ExtractMethod)]
+        public async Task BrokenForeachLoop()
+        {
+            var code = @"using System;
+namespace ConsoleApp1
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            [|Console.WriteLine(1);
+            foreach ()
+            Console.WriteLine(2);|]
+        }
+    }
+}";
+            var expected = @"using System;
+namespace ConsoleApp1
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            NewMethod();
+        }
+
+        private static void NewMethod()
+        {
+            Console.WriteLine(1);
+            foreach ()
+                Console.WriteLine(2);
+        }
+    }
+}";
+
+            await TestExtractMethodAsync(code, expected);
+        }
     }
 }