Check for empty location in ViewsFeatureProvider

Fixes #5675

src/Microsoft.AspNetCore.Mvc.Razor/Compilation/ViewsFeatureProvider.cs

@@ -58,7 +58,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Compilation
         protected virtual Type GetViewInfoContainerType(AssemblyPart assemblyPart)
         {
 #if NETSTANDARD1_6
-            if (!assemblyPart.Assembly.IsDynamic && assemblyPart.Assembly.Location != null)
+            if (!assemblyPart.Assembly.IsDynamic && !string.IsNullOrEmpty(assemblyPart.Assembly.Location))
             {
                 var precompiledAssemblyFileName = assemblyPart.Assembly.GetName().Name
                     + PrecompiledViewsAssemblySuffix

test/Microsoft.AspNetCore.Mvc.Razor.Test/Compilation/ViewsFeatureProviderTest.cs

@@ -90,6 +90,23 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Compilation
             Assert.Empty(feature.Views);
         }
 
+        [Fact]
+        public void PopulateFeature_DoesNotFail_IfAssemblyHasEmptyLocation()
+        {
+            // Arrange
+            var assembly = new AssemblyWithEmptyLocation();
+            var applicationPartManager = new ApplicationPartManager();
+            applicationPartManager.ApplicationParts.Add(new AssemblyPart(assembly));
+            applicationPartManager.FeatureProviders.Add(new ViewsFeatureProvider());
+            var feature = new ViewsFeature();
+
+            // Act
+            applicationPartManager.PopulateFeature(feature);
+
+            // Assert
+            Assert.Empty(feature.Views);
+        }
+
         private class TestableViewsFeatureProvider : ViewsFeatureProvider
         {
             private readonly Dictionary<AssemblyPart, Type> _containerLookup;
@@ -125,5 +142,12 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Compilation
             {
             }
         }
+
+        private class AssemblyWithEmptyLocation : Assembly
+        {
+            public override string Location => string.Empty;
+
+            public override string FullName => typeof(ViewsFeatureProviderTest).GetTypeInfo().Assembly.FullName;
+        }
     }
 }