From 72b3f46b435b7e3c662e34ecefdd1e66e59d3092 Mon Sep 17 00:00:00 2001
From: Michael Howell <michael@notriddle.com>
Date: Sat, 11 Feb 2023 12:36:55 -0700
Subject: [PATCH] rustdoc: account for intra-doc links in `<meta
 name="description">`

---
 src/librustdoc/html/markdown.rs       | 13 +++++++++++--
 src/librustdoc/html/markdown/tests.rs |  2 +-
 src/librustdoc/html/render/context.rs |  5 ++++-
 tests/rustdoc/description.rs          |  6 ++++++
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index dee0a01a65413..0ff73eb79de03 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -1180,14 +1180,23 @@ pub(crate) fn short_markdown_summary(markdown: &str, link_names: &[RenderedLink]
 /// - Headings, links, and formatting are stripped.
 /// - Inline code is rendered as-is, surrounded by backticks.
 /// - HTML and code blocks are ignored.
-pub(crate) fn plain_text_summary(md: &str) -> String {
+pub(crate) fn plain_text_summary(md: &str, link_names: &[RenderedLink]) -> String {
     if md.is_empty() {
         return String::new();
     }
 
     let mut s = String::with_capacity(md.len() * 3 / 2);
 
-    for event in Parser::new_ext(md, summary_opts()) {
+    let mut replacer = |broken_link: BrokenLink<'_>| {
+        link_names
+            .iter()
+            .find(|link| link.original_text.as_str() == &*broken_link.reference)
+            .map(|link| (link.href.as_str().into(), link.new_text.as_str().into()))
+    };
+
+    let p = Parser::new_with_broken_link_callback(md, summary_opts(), Some(&mut replacer));
+
+    for event in p {
         match &event {
             Event::Text(text) => s.push_str(text),
             Event::Code(code) => {
diff --git a/src/librustdoc/html/markdown/tests.rs b/src/librustdoc/html/markdown/tests.rs
index 5878c58264ec3..e05635a020756 100644
--- a/src/librustdoc/html/markdown/tests.rs
+++ b/src/librustdoc/html/markdown/tests.rs
@@ -249,7 +249,7 @@ fn test_short_markdown_summary() {
 #[test]
 fn test_plain_text_summary() {
     fn t(input: &str, expect: &str) {
-        let output = plain_text_summary(input);
+        let output = plain_text_summary(input, &[]);
         assert_eq!(output, expect, "original: {}", input);
     }
 
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index 1216a8d71c8cf..6762fba9275cf 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -182,7 +182,10 @@ impl<'tcx> Context<'tcx> {
         };
         title.push_str(" - Rust");
         let tyname = it.type_();
-        let desc = it.doc_value().as_ref().map(|doc| plain_text_summary(doc));
+        let desc = it
+            .doc_value()
+            .as_ref()
+            .map(|doc| plain_text_summary(doc, &it.link_names(&self.cache())));
         let desc = if let Some(desc) = desc {
             desc
         } else if it.is_crate() {
diff --git a/tests/rustdoc/description.rs b/tests/rustdoc/description.rs
index 05ec428220847..43cd59ebd0924 100644
--- a/tests/rustdoc/description.rs
+++ b/tests/rustdoc/description.rs
@@ -22,3 +22,9 @@ pub mod foo_mod {
 //   'Only paragraph.'
 /// Only paragraph.
 pub fn foo_fn() {}
+
+// @has 'foo/fn.bar_fn.html' '//meta[@name="description"]/@content' \
+//   'Description with intra-doc link to foo_fn and [nonexistent_item] and foo_fn.'
+#[allow(rustdoc::broken_intra_doc_links)]
+/// Description with intra-doc link to [foo_fn] and [nonexistent_item] and [foo_fn](self::foo_fn).
+pub fn bar_fn() {}