[Fixes #2547] Fixed attribute value prefix with dynamic content being ignored

src/Microsoft.AspNet.Mvc.Razor/RazorPage.cs

@@ -548,7 +548,8 @@ namespace Microsoft.AspNet.Mvc.Razor
                         WritePositionTaggedLiteral(writer, prefix);
                         first = false;
                     }
-                    else
+
+                    if (!string.IsNullOrEmpty(attrVal.Prefix))
                     {
                         WritePositionTaggedLiteral(writer, attrVal.Prefix);
                     }

test/Microsoft.AspNet.Mvc.FunctionalTests/BasicTests.cs

@@ -76,6 +76,24 @@ namespace Microsoft.AspNet.Mvc.FunctionalTests
             Assert.Equal(expectedContent, responseContent);
         }
 
+        [Fact]
+        public async Task ViewWithAttributePrefix_RendersWithoutIgnoringPrefix()
+        {
+            // Arrange
+            var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
+            var client = server.CreateClient();
+            var expectedContent = await _resourcesAssembly.ReadResourceAsStringAsync(
+                "compiler/resources/BasicWebSite.Home.ViewWithPrefixedAttributeValue.html");
+
+            // Act
+            var response = await client.GetAsync("http://localhost/Home/ViewWithPrefixedAttributeValue");
+            var responseContent = await response.Content.ReadAsStringAsync();
+
+            // Assert
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            Assert.Equal(expectedContent, responseContent);
+        }
+
         [Fact]
         public async Task CanReturn_ResultsWithoutContent()
         {

test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/BasicWebSite.Home.ViewWithPrefixedAttributeValue.html

@@ -0,0 +1,5 @@
+
+
+<span foo="   abc" />
+<span bar="   Baz" />
+<span baz="   Baz   Baz" />

test/Microsoft.AspNet.Mvc.Razor.Test/RazorPageTest.cs

@@ -667,6 +667,8 @@ namespace Microsoft.AspNet.Mvc.Razor
             var sequence = new MockSequence();
             context.InSequence(sequence).Setup(f => f.BeginContext(0, 6, true)).Verifiable();
             context.InSequence(sequence).Setup(f => f.EndContext()).Verifiable();
+            context.InSequence(sequence).Setup(f => f.BeginContext(0, 6, true)).Verifiable();
+            context.InSequence(sequence).Setup(f => f.EndContext()).Verifiable();
             context.InSequence(sequence).Setup(f => f.BeginContext(8, 14, true)).Verifiable();
             context.InSequence(sequence).Setup(f => f.EndContext()).Verifiable();
             context.InSequence(sequence).Setup(f => f.BeginContext(22, 7, true)).Verifiable();

test/WebSites/BasicWebSite/Controllers/HomeController.cs

@@ -86,7 +86,12 @@ namespace BasicWebSite.Controllers
         {
             return View();
         }
-        
+
+        public IActionResult ViewWithPrefixedAttributeValue()
+        {
+            return View();
+        }
+
         public string GetApplicationDescription()
         {
             var actionDescriptor = (ControllerActionDescriptor)ActionContext.ActionDescriptor;

test/WebSites/BasicWebSite/Views/Home/ViewWithPrefixedAttributeValue.cshtml

@@ -0,0 +1,7 @@
+@{
+    var attrValue = "Baz";
+}
+
+<span foo="   abc" />
+<span bar="   @attrValue" />
+<span baz="   @attrValue   @attrValue" />