Razor does not respect html comments inside a razor block

[yishaigalatzer]

See original comment - https://aspnetwebstack.codeplex.com/workitem/2233

Does not work

@{
    <!-- Hello, I'm a comment that will break razor --->
}

Works

    <!-- Hello, I'm a comment that will break razor --->

If you have more than 2 dashes at the end of the comment - Razor shows compilation error. Only 2 dashes are accepted. However, if this comment is outside a code block, it works fine.

[dougbu]

@yishaigalatzer HTML 5 (like XML) disallows ending a comment with --->. should Razor ignore the issue (everywhere), warn, or do something else? I agree the behaviour should be consistent regardless of C# block versus HTML context.

just out of interest, does

@{
  <text><!-- Hello, I'm a comment that will break razor --></text>
}

or the same with the not-well-formed triple-dash comment result in a generated HTML comment?

[yishaigalatzer]

Browsers do allow it, so we can be nicer about it

[am11]

This issue is scoped to odd number of hyphens before CloseAngle in endSequence.
I think this patch will fix the issue:

diff --git a/src/Microsoft.AspNet.Razor/Parser/HtmlLanguageCharacteristics.cs b/src/Microsoft.AspNet.Razor/Parser/HtmlLanguageCharacteristics.cs
index dfb1c5e..4a35c33 100644
--- a/src/Microsoft.AspNet.Razor/Parser/HtmlLanguageCharacteristics.cs
+++ b/src/Microsoft.AspNet.Razor/Parser/HtmlLanguageCharacteristics.cs
@@ -43,6 +43,8 @@ public override string GetSample(HtmlSymbolType type)
                     return "?";
                 case HtmlSymbolType.DoubleHyphen:
                     return "--";
+                case HtmlSymbolType.SingleHyphen:
+                    return "-";
                 case HtmlSymbolType.LeftBracket:
                     return "[";
                 case HtmlSymbolType.CloseAngle:
diff --git a/src/Microsoft.AspNet.Razor/Parser/HtmlMarkupParser.Block.cs b/src/Microsoft.AspNet.Razor/Parser/HtmlMarkupParser.Block.cs
index 0f6a6d5..4ecd074 100644
--- a/src/Microsoft.AspNet.Razor/Parser/HtmlMarkupParser.Block.cs
+++ b/src/Microsoft.AspNet.Razor/Parser/HtmlMarkupParser.Block.cs
@@ -252,7 +252,11 @@ private bool BangTag()
                 if (CurrentSymbol.Type == HtmlSymbolType.DoubleHyphen)
                 {
                     AcceptAndMoveNext();
-                    return AcceptUntilAll(HtmlSymbolType.DoubleHyphen, HtmlSymbolType.CloseAngle);
+                    while(CurrentSymbol.Type == HtmlSymbolType.SingleHyphen)
+                    {
+                        AcceptAndMoveNext();
+                    }
+                    return AcceptUntilAll(HtmlSymbolType.CloseAngle);
                 }
                 else if (CurrentSymbol.Type == HtmlSymbolType.LeftBracket)
                 {
diff --git a/src/Microsoft.AspNet.Razor/Tokenizer/Symbols/HtmlSymbolType.cs b/src/Microsoft.AspNet.Razor/Tokenizer/Symbols/HtmlSymbolType.cs
index 27cbd7e..ab27157 100644
--- a/src/Microsoft.AspNet.Razor/Tokenizer/Symbols/HtmlSymbolType.cs
+++ b/src/Microsoft.AspNet.Razor/Tokenizer/Symbols/HtmlSymbolType.cs
@@ -17,6 +17,7 @@ public enum HtmlSymbolType
         ForwardSlash, // /
         QuestionMark, // ?
         DoubleHyphen, // --
+        SingleHyphen, // -
         LeftBracket, // [
         CloseAngle, // >
         RightBracket, // ]

[Eilon]

@NTaylorMullen can you verify if this is fixed? If so, please add a test for it.

[NTaylorMullen]

Yup, this is fixed 😄

[Eilon]

And there's a test for this exact case?

[NTaylorMullen]

Yup 😄

[Eilon]

Actually I don't see that case there. This particular case has 2 dashes <!-- and then 3 dashes --->. Can we add this specific case in case that has some bizarre impact on this case?

[Eilon]

(All the cases in that test have a matching number of dashes.)

[NTaylorMullen]

Can we add this specific case in case that has some bizarre impact on this case?

Sure

[rynowak]

Let's just add this test and close this out.

[NTaylorMullen]

49e3533