Incomplete HTML in .AlertTitle and .Text of Blockquote render hooks

[Lruihao]

Reproduce Steps

Given the following Markdown:

> [!NOTE] Hugo

> [!NOTE] _Hugo_
> The world’s fastest framework for building websites

> [!NOTE] **Hugo**

> [!TIP] **Hugo** FixIt

and the following render-blockquote-alert.html

{{ warnf "%s\t%s" .AlertTitle .Text }}

Actual results is .AlertTitle lost the trailing > and .Text in a start <p> without a closing tag:

WARN  Hugo      <p>
WARN  <em>Hugo</em      <p>The world’s fastest framework for building websites</p>
WARN  <strong>Hugo</strong      <p>
WARN  <strong>Hugo</strong> FixIt       <p>

Expected results (complete .AlertTitle and .Text):

WARN  Hugo      <p></p>
WARN  <em>Hugo</em>      <p>The world’s fastest framework for building websites</p>
WARN  <strong>Hugo</strong>      <p></p>
WARN  <strong>Hugo</strong> FixIt       <p></p>

BTW, if content body of alert is empty, .Text return nil seems better.

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

hugo v0.135.0+extended darwin/arm64 BuildDate=2024-09-27T13:17:08Z VendorInfo=brew

Does this issue reproduce with the latest release?

Yes

[Lruihao]

@bep Excuse me, could you take a look at this issue, please! 🙏

I think these problems should be in the following two places, but I am not familiar with go and don't know how to correct them. Can anyone help me?

hugo/markup/goldmark/blockquotes/blockquotes.go

Lines 87 to 92 in ffb41d1

	if typ == typeAlert {
	// Trim preamble: <p>[!NOTE]<br>\n but preserve leading paragraph.
	// We could possibly complicate this by moving this to the parser, but
	// keep it simple for now.
	text = "<p>" + text[strings.Index(text, "\n")+1:]
	}

hugo/markup/goldmark/blockquotes/blockquotes.go

Lines 162 to 177 in ffb41d1

	var blockQuoteAlertRe = regexp.MustCompile(`^<p>\[!([a-zA-Z]+)\](-|\+)?[^\S\r\n]?([^\n]*)\n?`)
	func resolveBlockQuoteAlert(s string) blockQuoteAlert {
	m := blockQuoteAlertRe.FindStringSubmatch(s)
	if len(m) == 4 {
	title := strings.TrimSpace(m[3])
	title = strings.TrimRight(title, "</p>")
	return blockQuoteAlert{
	typ: strings.ToLower(m[1]),
	sign: m[2],
	title: title,
	}
	}
	return blockQuoteAlert{}
	}