From 427b6dbcbb21302cc55935fbcf84d9ac03bd9fd2 Mon Sep 17 00:00:00 2001
From: Turiiya <34311583+ttytm@users.noreply.github.com>
Date: Mon, 8 Apr 2024 17:45:51 +0200
Subject: [PATCH] vdoc: improve line merging for readme contents (#21224)

---
 cmd/tools/vdoc/html.v                         | 21 +++++++++++++++++--
 .../tests/testdata/output_formats/main.html   |  2 +-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/cmd/tools/vdoc/html.v b/cmd/tools/vdoc/html.v
index e2320d7056..bfbea197b4 100644
--- a/cmd/tools/vdoc/html.v
+++ b/cmd/tools/vdoc/html.v
@@ -501,8 +501,25 @@ fn doc_node_html(dn doc.DocNode, link string, head bool, include_examples bool,
 	head_tag := if head { 'h1' } else { 'h2' }
 	// Allow README.md to go through unescaped except for script tags
 	escaped_html := if head && is_module_readme(dn) {
-		// Strip markdown [TOC] directives, since we generate our own.
-		dn.comments[0].text
+		readme_lines := dn.comments[0].text.split_into_lines()
+		mut merged_lines := []string{}
+		mut is_codeblock := false
+		for i := 0; i < readme_lines.len - 1; i++ {
+			l := readme_lines[i]
+			nl := readme_lines[i + 1]
+			is_codeblock_divider := l.trim_left('\x01').trim_space().starts_with('```')
+			if is_codeblock_divider {
+				is_codeblock = !is_codeblock
+			}
+			if !is_codeblock && !is_codeblock_divider && l != '' && nl != ''
+				&& !nl.trim_left('\x01').trim_space().starts_with('```') {
+				merged_lines << '${l} ${nl}'
+				i++
+				continue
+			}
+			merged_lines << l
+		}
+		merged_lines.join_lines()
 	} else {
 		dn.merge_comments()
 	}
diff --git a/cmd/tools/vdoc/tests/testdata/output_formats/main.html b/cmd/tools/vdoc/tests/testdata/output_formats/main.html
index 748c7180a2..5161433786 100644
--- a/cmd/tools/vdoc/tests/testdata/output_formats/main.html
+++ b/cmd/tools/vdoc/tests/testdata/output_formats/main.html
@@ -1,6 +1,6 @@
 <section id="readme_main" class="doc-node">
 			<div class="title"><h1> main <a href="#readme_main">#</a></h1></div>
-<h2>Description</h2><p>This is an example of a an .md file, used for adding more rich textdocumentation in a project or module.</p><p>This is a <a href="https://vlang.io/">link</a> to the main V site.</p><p>This is a <b>bold text</b>.</p><p>This is a script <code>&lt;script&gt;console.log('hi from README.md');&lt;/script&gt;</code> .</p><h2>Examples</h2><h3>Processing command line args</h3><pre><code class="language-v"><span class="token keyword">import</span> os
+<h2>Description</h2><p>This is an example of a an .md file, used for adding more rich text documentation in a project or module.</p><p>This is a <a href="https://vlang.io/">link</a> to the main V site.</p><p>This is a <b>bold text</b>.</p><p>This is a script <code>&lt;script&gt;console.log('hi from README.md');&lt;/script&gt;</code> .</p><h2>Examples</h2><h3>Processing command line args</h3><pre><code class="language-v"><span class="token keyword">import</span> os
 
 <span class="token keyword">fn</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
     <span class="token keyword">dump</span><span class="token punctuation">(</span>os<span class="token punctuation">.</span>args<span class="token punctuation">)</span>