AST may be reporting the wrong length of HTML block

[mike-ward]

I don't know enough about the nuances of Markdown and the AST to know if this a bug so I'll just report it.

Given at the beginning of a document:

<pre>
</pre

The AST will report the HTML block begins at offset 0 with a length of 12

Close the tag however:

<pre>
</pre>

And the AST reports the block begins at offset 0 with a length of 7.

Reported in https://github.com/mike-ward/Markdown-Edit/issues/165

[Knagis]

This is because the incomplete </pre does not close the HTML block so it will continue on the following lines (including any newlines). </pre> however does close it.

try.commonmark.org

<pre>, <style> and <script> tags are special this way. See HTML Block Type 1 from commonmark specification

[mike-ward]

I'm not sure I follow. The block gets shorter when the tag is closed. Shouldn't it be longer?

From the spec:

It ends with the first subsequent line that meets a matching end condition, or the last line of the document, if no line is encountered that meets the end condition.

[Knagis]

OK, I see now - the problem is that the length of 7 is not inclusive of the last line.

Yes, that is a bug, I will see to fix is asap.

[mike-ward]

I should have made that clear in the original report. Too close to the problem to describe correctly.

[Knagis]

0.13.3 has been pushed to nuget. Hopefully it fixes the issue.

[mike-ward]

Tested it out. It does fix the problem but introduces another issue. If I start with

<pre>
</pre>

and backspace over the last closing > an exception is thrown.

CommonMark.CommonMarkException was unhandled by user code
  HResult=-2146233088
  Message=An error occurred while finalizing open containers.
  Source=CommonMark
  StackTrace:
       at CommonMark.CommonMarkConverter.ProcessStage1(TextReader source, CommonMarkSettings settings) in E:\OneDrive\Programming\CommonMark\CommonMark\CommonMarkConverter.cs:line 145
       at MarkdownEdit.Models.Markdown.GenerateAbstractSyntaxTree(String text) in C:\Users\mike\GitHub\Markdown-Edit\src\MarkdownEdit\Models\Markdown.cs:line 198
       at MarkdownEdit.Models.Markdown.ToHtml(String markdown) in C:\Users\mike\GitHub\Markdown-Edit\src\MarkdownEdit\Models\Markdown.cs:line 58
       at MarkdownEdit.Controls.Preview.<>c__DisplayClass32_1.<Update>b__0() in C:\Users\mike\GitHub\Markdown-Edit\src\MarkdownEdit\Controls\Preview.xaml.cs:line 102
       at System.Threading.Tasks.Task.Execute()
  InnerException: 
       HResult=-2147467261
       Message=Object reference not set to an instance of an object.
       Source=CommonMark
       StackTrace:
            at CommonMark.Parser.BlockMethods.Finalize(Block b, LineInfo line) in E:\OneDrive\Programming\CommonMark\CommonMark\Parser\BlockMethods.cs:line 122
            at CommonMark.CommonMarkConverter.ProcessStage1(TextReader source, CommonMarkSettings settings) in E:\OneDrive\Programming\CommonMark\CommonMark\CommonMarkConverter.cs:line 135
       InnerException: 

[Knagis]

This should be fixed now in 0.13.4

[mike-ward]

Yep, that fixes it. Thanks!