diff --git a/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj b/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
index 68115c61d7..7eab76a93d 100644
--- a/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
+++ b/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
@@ -240,6 +240,7 @@
+
diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExplicitConversionInForEachIssue.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExplicitConversionInForEachIssue.cs
new file mode 100644
index 0000000000..4bce89dabf
--- /dev/null
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ExplicitConversionInForEachIssue.cs
@@ -0,0 +1,73 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Collections.Generic;
+using ICSharpCode.NRefactory.CSharp.Resolver;
+using ICSharpCode.NRefactory.Semantics;
+using ICSharpCode.NRefactory.TypeSystem;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+ [IssueDescription("Incorrect element type in foreach over generic collection",
+ Description= "Detects hidden explicit conversions in foreach loops.",
+ Category = IssueCategories.CodeQualityIssues,
+ Severity = Severity.Warning)]
+ public class ExplicitConversionInForEachIssue : ICodeIssueProvider
+ {
+ public IEnumerable GetIssues (BaseRefactoringContext context)
+ {
+ var visitor = new GatherVisitor (context);
+ context.RootNode.AcceptVisitor (visitor);
+ return visitor.FoundIssues;
+ }
+
+ class GatherVisitor : GatherVisitorBase
+ {
+ CSharpConversions conversions;
+
+ public GatherVisitor (BaseRefactoringContext ctx) : base (ctx)
+ {
+ }
+
+ public override void VisitForeachStatement(ForeachStatement foreachStatement)
+ {
+ base.VisitForeachStatement(foreachStatement);
+ var rr = ctx.Resolve(foreachStatement) as ForEachResolveResult;
+ if (rr == null)
+ return;
+ if (rr.ElementType.Kind == TypeKind.Unknown)
+ return;
+ if (ReflectionHelper.GetTypeCode(rr.ElementType) == TypeCode.Object)
+ return;
+ if (conversions == null) {
+ conversions = CSharpConversions.Get(ctx.Compilation);
+ }
+ Conversion c = conversions.ImplicitConversion(rr.ElementType, rr.ElementVariable.Type);
+ if (c.IsValid)
+ return;
+ var csResolver = ctx.GetResolverStateBefore(foreachStatement);
+ var builder = new TypeSystemAstBuilder(csResolver);
+ AstType elementType = builder.ConvertType(rr.ElementType);
+ AstType variableType = foreachStatement.VariableType;
+ string text = ctx.TranslateString("Collection element type '{0}' is not implicitly convertible to '{1}'");
+ AddIssue(variableType, string.Format(text, elementType.GetText(), variableType.GetText()));
+ }
+ }
+ }
+}
diff --git a/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExplicitConversionInForEachIssueTests.cs b/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExplicitConversionInForEachIssueTests.cs
new file mode 100644
index 0000000000..a0fcd50d78
--- /dev/null
+++ b/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ExplicitConversionInForEachIssueTests.cs
@@ -0,0 +1,75 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using ICSharpCode.NRefactory.CSharp.CodeActions;
+using ICSharpCode.NRefactory.CSharp.Refactoring;
+using NUnit.Framework;
+
+namespace ICSharpCode.NRefactory.CSharp.CodeIssues
+{
+ [TestFixture]
+ public class ExplicitConversionInForEachIssueTests : InspectionActionTestBase
+ {
+ [Test]
+ public void NoWarningOnNonGenericCollection ()
+ {
+ var input = @"class Foo {
+ void Bar (System.Collections.ArrayList c)
+ {
+ foreach (string element in c) { }
+ }
+}";
+
+ TestRefactoringContext context;
+ var issues = GetIssues (new ExplicitConversionInForEachIssue (), input, out context);
+ Assert.AreEqual (0, issues.Count);
+ }
+
+ [Test]
+ public void NoWarningOnImplicitConversion ()
+ {
+ var input = @"class Foo {
+ void Bar (System.Collections.Generic.List c)
+ {
+ foreach (double element in c) { }
+ }
+}";
+
+ TestRefactoringContext context;
+ var issues = GetIssues (new ExplicitConversionInForEachIssue (), input, out context);
+ Assert.AreEqual (0, issues.Count);
+ }
+
+ [Test]
+ public void WarningOnExplicitConversionBetweenInterfaces ()
+ {
+ var input = @"using System.Collections.Generic;
+class Foo {
+ void Bar (IList> c)
+ {
+ foreach (IDisposable element in c) { }
+ }
+}";
+
+ TestRefactoringContext context;
+ var issues = GetIssues (new ExplicitConversionInForEachIssue (), input, out context);
+ Assert.AreEqual (1, issues.Count);
+ }
+ }
+}
diff --git a/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj b/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
index 63a6c799e8..4731483331 100644
--- a/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
+++ b/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
@@ -81,6 +81,7 @@
+