Fix: Index out of bounds for incomplete attribute value

- #555
- Added a unit and a code generation test

src/Microsoft.AspNet.Razor/Parser/TagHelpers/TagHelperBlockRewriter.cs

@@ -215,34 +215,29 @@ namespace Microsoft.AspNet.Razor.Parser.TagHelpers.Internal
 
                     // The coming symbols will either be a quote or value (in the case that the value is unquoted).
 
-                    // TODO: Handle malformed tags, if there's an '=' then there MUST be a value.
-                    // https://github.com/aspnet/Razor/issues/104
-
                     SourceLocation symbolStartLocation;
 
                     // Skip the whitespace preceding the start of the attribute value.
-                    var valueStartIndex = i + 1; // Start from the symbol after '='.
+                    do
-                    while (valueStartIndex < htmlSymbols.Length &&
-                        (htmlSymbols[valueStartIndex].Type == HtmlSymbolType.WhiteSpace ||
-                        htmlSymbols[valueStartIndex].Type == HtmlSymbolType.NewLine))
                     {
-                        valueStartIndex++;
+                        i++; // Start from the symbol after '='.
-                    }
+                    } while (i < htmlSymbols.Length &&
+                        (htmlSymbols[i].Type == HtmlSymbolType.WhiteSpace ||
+                        htmlSymbols[i].Type == HtmlSymbolType.NewLine));
 
                     // Check for attribute start values, aka single or double quote
-                    if (valueStartIndex < htmlSymbols.Length && IsQuote(htmlSymbols[valueStartIndex]))
+                    if (i < htmlSymbols.Length && IsQuote(htmlSymbols[i]))
                     {
-                        // Move past the attribute start so we can accept the true value.
+                        symbolStartLocation = htmlSymbols[i].Start;
-                        valueStartIndex++;
-                        symbolStartLocation = htmlSymbols[valueStartIndex].Start;
 
                         // If there's a start quote then there must be an end quote to be valid, skip it.
                         symbolOffset = 1;
-
-                        i = valueStartIndex - 1;
                     }
                     else
                     {
+                        // We are at the symbol after equals. Go back to equals to ensure we don't skip past that symbol.
+                        i--;
+
                         symbolStartLocation = symbol.Start;
                     }
 

test/Microsoft.AspNet.Razor.Test/CodeGenerators/CSharpTagHelperRenderingTest.cs

@@ -920,9 +920,9 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                                 characterOffsetIndex: 14,
                                 contentLength: 11),
                             BuildLineMapping(
-                                documentAbsoluteIndex: 63,
+                                documentAbsoluteIndex: 62,
                                 documentLineIndex: 3,
-                                documentCharacterOffsetIndex: 27,
+                                documentCharacterOffsetIndex: 26,
                                 generatedAbsoluteIndex: 1289,
                                 generatedLineIndex: 39,
                                 generatedCharacterOffsetIndex: 28,
@@ -935,9 +935,9 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                                 characterOffsetIndex: 30,
                                 contentLength: 0),
                             BuildLineMapping(
-                                documentAbsoluteIndex: 89,
+                                documentAbsoluteIndex: 88,
                                 documentLineIndex: 4,
-                                documentCharacterOffsetIndex: 13,
+                                documentCharacterOffsetIndex: 12,
                                 generatedAbsoluteIndex: 1789,
                                 generatedLineIndex: 54,
                                 generatedCharacterOffsetIndex: 19,
@@ -1650,6 +1650,7 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                 // Note: The baseline resource name is equivalent to the test resource name.
                 return new TheoryData<string, string, IEnumerable<TagHelperDescriptor>>
                 {
+                    { "IncompleteTagHelper", null, DefaultPAndInputTagHelperDescriptors },
                     { "SingleTagHelper", null, DefaultPAndInputTagHelperDescriptors },
                     { "SingleTagHelperWithNewlineBeforeAttributes", null, DefaultPAndInputTagHelperDescriptors },
                     { "TagHelpersWithWeirdlySpacedAttributes", null, DefaultPAndInputTagHelperDescriptors },

test/Microsoft.AspNet.Razor.Test/TagHelpers/TagHelperBlockRewriterTest.cs

@@ -377,12 +377,21 @@ namespace Microsoft.AspNet.Razor.TagHelpers
                 return new TheoryData<string, MarkupBlock, RazorError[]>
                 {
                     {
-                        "<p =\"false\"\" ></p>",
+                        "<p class='",
                         new MarkupBlock(
                             new MarkupTagHelperBlock("p",
-                                new List<KeyValuePair<string, SyntaxTreeNode>>())),
+                                new List<KeyValuePair<string, SyntaxTreeNode>>
+                                {
+                                    new KeyValuePair<string, SyntaxTreeNode>(
+                                        "class",
+                                        factory.Markup(string.Empty).With(SpanChunkGenerator.Null))
+                                })),
                         new []
                         {
+                            new RazorError(
+                                string.Format(CultureInfo.InvariantCulture, errorFormatNoCloseAngle, "p"),
+                                new SourceLocation(1, 0, 1),
+                                length: 1),
                             new RazorError(
                                 string.Format(CultureInfo.InvariantCulture, errorFormatUnclosed, "p"),
                                 new SourceLocation(1, 0, 1),

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/Output/IncompleteTagHelper.cs

@@ -0,0 +1,44 @@
+#pragma checksum "IncompleteTagHelper.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "dba409dce3afe321d920e4e62a5701c09d7bbea8"
+namespace TestOutput
+{
+    using Microsoft.AspNet.Razor.Runtime.TagHelpers;
+    using System;
+    using System.Threading.Tasks;
+
+    public class IncompleteTagHelper
+    {
+        #line hidden
+        #pragma warning disable 0414
+        private TagHelperContent __tagHelperStringValueBuffer = null;
+        #pragma warning restore 0414
+        private TagHelperExecutionContext __tagHelperExecutionContext = null;
+        private TagHelperRunner __tagHelperRunner = null;
+        private TagHelperScopeManager __tagHelperScopeManager = new TagHelperScopeManager();
+        private PTagHelper __PTagHelper = null;
+        #line hidden
+        public IncompleteTagHelper()
+        {
+        }
+
+        #pragma warning disable 1998
+        public override async Task ExecuteAsync()
+        {
+            __tagHelperRunner = __tagHelperRunner ?? new TagHelperRunner();
+            Instrumentation.BeginContext(33, 2, true);
+            WriteLiteral("\r\n");
+            Instrumentation.EndContext();
+            __tagHelperExecutionContext = __tagHelperScopeManager.Begin("p", TagMode.StartTagAndEndTag, "test", async() => {
+            }
+            , StartTagHelperWritingScope, EndTagHelperWritingScope);
+            __PTagHelper = CreateTagHelper<PTagHelper>();
+            __tagHelperExecutionContext.Add(__PTagHelper);
+            __tagHelperExecutionContext.AddHtmlAttribute("class", Html.Raw(""));
+            __tagHelperExecutionContext.Output = await __tagHelperRunner.RunAsync(__tagHelperExecutionContext);
+            Instrumentation.BeginContext(35, 10, false);
+            await WriteTagHelperAsync(__tagHelperExecutionContext);
+            Instrumentation.EndContext();
+            __tagHelperExecutionContext = __tagHelperScopeManager.End();
+        }
+        #pragma warning restore 1998
+    }
+}

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/Source/IncompleteTagHelper.cshtml

@@ -0,0 +1,3 @@
+@addTagHelper "something, nice"
+
+<p class="