unexpected trailing dash in auto heading ID for "# heading #"

[lukpank]

What version of Hugo are you using (hugo version)?

$ hugo version
Hugo Static Site Generator v0.63.1/extended linux/amd64 BuildDate: unknown

The issue originates in the following commit:

a82d2700 markup/goldmark: Make auto IDs GitHub compatible

Does this issue reproduce with the latest release?

Yes

Problematic document

Having the following markdown document (note trailing space after "Heading2"):

# Heading1 #
# Heading2 

Correct auto heading IDs with blackFriday

If I turn on the "blackFriday" markdown parser with:

[markup]
  defaultMarkdownHandler = "blackFriday"

The generated heading IDs are both correct (no trailing dash):

$ ( hugo && grep 'h1 id=' public/tmp/index.html ) | tail -2
<h1 id="heading1">Heading1</h1>
<h1 id="heading2">Heading2</h1>

Incorrect heading ID with goldmark

But If I use the default "goldmark" Markdown parser the generated ID
for the first heading contains unexpected trailing dash:

$ ( hugo && grep 'h1 id=' public/tmp/index.html ) | tail -2
  <h1 id="heading1-">Heading1</h1>
<h1 id="heading2">Heading2</h1>

Input to Generate

I checked what enters (*idFactory).Generate (from markup/goldmark/autoid.go) and for the first heading the input converted to string is "Heading1 " (has a trailing space) and for the second heading it is "Heading2".

[obar]

Ran into the same thing (trailing whitespace not trimmed in symmetric heading style) and my solution was to use the asymmetric heading style. Any reason not to file this as a bug in goldmark and close this one?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. The resources of the Hugo team are limited, and so we are asking for your help.
If this is a bug and you can still reproduce this error on the master branch, please reply with all of the information you have about it in order to keep the issue open.
If this is a feature request, and you feel that it is still relevant and valuable, please tell us why.
This issue will automatically be closed in the near future if no further activity occurs. Thank you for all your contributions.

[jmooring]

Please reopen:

• This is reproducible with 0.73
• It does not appear to be a Goldmark bug (hugo-github-issue-6798.go.txt)
• Reproducible with autoHeadingIDType set to either github or github-ascii
• Not reproducible with autoHeadingIDType set to blackfriday

Examples:

Markdown	Expected HTML	Actual HTML
# Foo #	<h1 id="foo">Foo</h1>	<h1 id="foo-">Foo</h1>
# Bar {.foo}	<h1 class="foo" id="bar">Bar</h1>	<h1 class="foo" id="bar-">Bar</h1>

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.