Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

20 files changed, 366 insertions, 168 deletions

diff --git a/vendor/mdbook/src/book/book.rs b/vendor/mdbook/src/book/book.rs
index b46843df5..96c70abc4 100644
--- a/vendor/mdbook/src/book/book.rs
+++ b/vendor/mdbook/src/book/book.rs
@@ -39,9 +39,7 @@ fn create_missing(src_dir: &Path, summary: &Summary) -> Result<()> {
         .chain(summary.suffix_chapters.iter())
         .collect();
 
-    while !items.is_empty() {
-        let next = items.pop().expect("already checked");
-
+    while let Some(next) = items.pop() {
         if let SummaryItem::Link(ref link) = *next {
             if let Some(ref location) = link.location {
                 let filename = src_dir.join(location);
@@ -277,7 +275,7 @@ fn load_chapter<P: AsRef<Path>>(
         }
 
         let stripped = location
-            .strip_prefix(&src_dir)
+            .strip_prefix(src_dir)
             .expect("Chapters are always inside a book");
 
         Chapter::new(&link.name, content, stripped, parent_names.clone())
@@ -317,7 +315,7 @@ impl<'a> Iterator for BookItems<'a> {
     fn next(&mut self) -> Option<Self::Item> {
         let item = self.items.pop_front();
 
-        if let Some(&BookItem::Chapter(ref ch)) = item {
+        if let Some(BookItem::Chapter(ch)) = item {
             // if we wanted a breadth-first iterator we'd `extend()` here
             for sub_item in ch.sub_items.iter().rev() {
                 self.items.push_front(sub_item);
diff --git a/vendor/mdbook/src/book/init.rs b/vendor/mdbook/src/book/init.rs
index ebcdd9349..faca1d09a 100644
--- a/vendor/mdbook/src/book/init.rs
+++ b/vendor/mdbook/src/book/init.rs
@@ -198,8 +198,7 @@ impl BookBuilder {
             writeln!(f, "- [Chapter 1](./chapter_1.md)")?;
 
             let chapter_1 = src_dir.join("chapter_1.md");
-            let mut f =
-                File::create(&chapter_1).with_context(|| "Unable to create chapter_1.md")?;
+            let mut f = File::create(chapter_1).with_context(|| "Unable to create chapter_1.md")?;
             writeln!(f, "# Chapter 1")?;
         } else {
             trace!("Existing summary found, no need to create stub files.");
@@ -212,10 +211,10 @@ impl BookBuilder {
         fs::create_dir_all(&self.root)?;
 
         let src = self.root.join(&self.config.book.src);
-        fs::create_dir_all(&src)?;
+        fs::create_dir_all(src)?;
 
         let build = self.root.join(&self.config.build.build_dir);
-        fs::create_dir_all(&build)?;
+        fs::create_dir_all(build)?;
 
         Ok(())
     }
diff --git a/vendor/mdbook/src/book/mod.rs b/vendor/mdbook/src/book/mod.rs
index 33fe93f7f..a5e3e78c6 100644
--- a/vendor/mdbook/src/book/mod.rs
+++ b/vendor/mdbook/src/book/mod.rs
@@ -99,7 +99,7 @@ impl MDBook {
         let root = book_root.into();
 
         let src_dir = root.join(&config.book.src);
-        let book = book::load_book(&src_dir, &config.build)?;
+        let book = book::load_book(src_dir, &config.build)?;
 
         let renderers = determine_renderers(&config);
         let preprocessors = determine_preprocessors(&config)?;
@@ -122,7 +122,7 @@ impl MDBook {
         let root = book_root.into();
 
         let src_dir = root.join(&config.book.src);
-        let book = book::load_book_from_disk(&summary, &src_dir)?;
+        let book = book::load_book_from_disk(&summary, src_dir)?;
 
         let renderers = determine_renderers(&config);
         let preprocessors = determine_preprocessors(&config)?;
@@ -309,7 +309,7 @@ impl MDBook {
                 info!("Testing chapter '{}': {:?}", ch.name, chapter_path);
 
                 // write preprocessed file to tempdir
-                let path = temp_dir.path().join(&chapter_path);
+                let path = temp_dir.path().join(chapter_path);
                 let mut tmpf = utils::fs::create_file(&path)?;
                 tmpf.write_all(ch.content.as_bytes())?;
 
@@ -319,13 +319,13 @@ impl MDBook {
                 if let Some(edition) = self.config.rust.edition {
                     match edition {
                         RustEdition::E2015 => {
-                            cmd.args(&["--edition", "2015"]);
+                            cmd.args(["--edition", "2015"]);
                         }
                         RustEdition::E2018 => {
-                            cmd.args(&["--edition", "2018"]);
+                            cmd.args(["--edition", "2018"]);
                         }
                         RustEdition::E2021 => {
-                            cmd.args(&["--edition", "2021"]);
+                            cmd.args(["--edition", "2021"]);
                         }
                     }
                 }
diff --git a/vendor/mdbook/src/cmd/build.rs b/vendor/mdbook/src/cmd/build.rs
index 14a9fec6e..e40e5c0c7 100644
--- a/vendor/mdbook/src/cmd/build.rs
+++ b/vendor/mdbook/src/cmd/build.rs
@@ -16,7 +16,7 @@ pub fn make_subcommand() -> Command {
 // Build command implementation
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
-    let mut book = MDBook::load(&book_dir)?;
+    let mut book = MDBook::load(book_dir)?;
 
     if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
         book.config.build.build_dir = dest_dir.into();
diff --git a/vendor/mdbook/src/cmd/clean.rs b/vendor/mdbook/src/cmd/clean.rs
index 3ec605fea..48b4147ca 100644
--- a/vendor/mdbook/src/cmd/clean.rs
+++ b/vendor/mdbook/src/cmd/clean.rs
@@ -16,7 +16,7 @@ pub fn make_subcommand() -> Command {
 // Clean command implementation
 pub fn execute(args: &ArgMatches) -> mdbook::errors::Result<()> {
     let book_dir = get_book_dir(args);
-    let book = MDBook::load(&book_dir)?;
+    let book = MDBook::load(book_dir)?;
 
     let dir_to_remove = match args.get_one::<PathBuf>("dest-dir") {
         Some(dest_dir) => dest_dir.into(),
diff --git a/vendor/mdbook/src/cmd/init.rs b/vendor/mdbook/src/cmd/init.rs
index d8ce93d16..2c6415b6d 100644
--- a/vendor/mdbook/src/cmd/init.rs
+++ b/vendor/mdbook/src/cmd/init.rs
@@ -56,7 +56,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
             "git" => builder.create_gitignore(true),
             _ => builder.create_gitignore(false),
         };
-    } else {
+    } else if !args.get_flag("force") {
         println!("\nDo you want a .gitignore to be created? (y/n)");
         if confirm() {
             builder.create_gitignore(true);
@@ -65,6 +65,8 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
 
     config.book.title = if args.contains_id("title") {
         args.get_one::<String>("title").map(String::from)
+    } else if args.get_flag("force") {
+        None
     } else {
         request_book_title()
     };
@@ -84,7 +86,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
 /// Obtains author name from git config file by running the `git config` command.
 fn get_author_name() -> Option<String> {
     let output = Command::new("git")
-        .args(&["config", "--get", "user.name"])
+        .args(["config", "--get", "user.name"])
         .output()
         .ok()?;
 
@@ -114,5 +116,5 @@ fn confirm() -> bool {
     io::stdout().flush().unwrap();
     let mut s = String::new();
     io::stdin().read_line(&mut s).ok();
-    matches!(&*s.trim(), "Y" | "y" | "yes" | "Yes")
+    matches!(s.trim(), "Y" | "y" | "yes" | "Yes")
 }
diff --git a/vendor/mdbook/src/cmd/serve.rs b/vendor/mdbook/src/cmd/serve.rs
index 88898567e..eeb19cb37 100644
--- a/vendor/mdbook/src/cmd/serve.rs
+++ b/vendor/mdbook/src/cmd/serve.rs
@@ -48,7 +48,7 @@ pub fn make_subcommand() -> Command {
 // Serve command implementation
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
-    let mut book = MDBook::load(&book_dir)?;
+    let mut book = MDBook::load(book_dir)?;
 
     let port = args.get_one::<String>("port").unwrap();
     let hostname = args.get_one::<String>("hostname").unwrap();
@@ -102,7 +102,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
         info!("Building book...");
 
         // FIXME: This area is really ugly because we need to re-set livereload :(
-        let result = MDBook::load(&book_dir).and_then(|mut b| {
+        let result = MDBook::load(book_dir).and_then(|mut b| {
             update_config(&mut b);
             b.build()
         });
diff --git a/vendor/mdbook/src/cmd/test.rs b/vendor/mdbook/src/cmd/test.rs
index 3efe130b1..69f99f409 100644
--- a/vendor/mdbook/src/cmd/test.rs
+++ b/vendor/mdbook/src/cmd/test.rs
@@ -44,7 +44,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     let chapter: Option<&str> = args.get_one::<String>("chapter").map(|s| s.as_str());
 
     let book_dir = get_book_dir(args);
-    let mut book = MDBook::load(&book_dir)?;
+    let mut book = MDBook::load(book_dir)?;
 
     if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
         book.config.build.build_dir = dest_dir.to_path_buf();
diff --git a/vendor/mdbook/src/cmd/watch.rs b/vendor/mdbook/src/cmd/watch.rs
index bbc6bde71..e9806e1cd 100644
--- a/vendor/mdbook/src/cmd/watch.rs
+++ b/vendor/mdbook/src/cmd/watch.rs
@@ -1,5 +1,6 @@
 use super::command_prelude::*;
 use crate::{get_book_dir, open};
+use ignore::gitignore::Gitignore;
 use mdbook::errors::Result;
 use mdbook::utils;
 use mdbook::MDBook;
@@ -20,7 +21,7 @@ pub fn make_subcommand() -> Command {
 // Watch command implementation
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
-    let mut book = MDBook::load(&book_dir)?;
+    let mut book = MDBook::load(book_dir)?;
 
     let update_config = |book: &mut MDBook| {
         if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
@@ -41,7 +42,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
 
     trigger_on_change(&book, |paths, book_dir| {
         info!("Files changed: {:?}\nBuilding book...\n", paths);
-        let result = MDBook::load(&book_dir).and_then(|mut b| {
+        let result = MDBook::load(book_dir).and_then(|mut b| {
             update_config(&mut b);
             b.build()
         });
@@ -62,14 +63,14 @@ fn remove_ignored_files(book_root: &Path, paths: &[PathBuf]) -> Vec<PathBuf> {
 
     match find_gitignore(book_root) {
         Some(gitignore_path) => {
-            match gitignore::File::new(gitignore_path.as_path()) {
-                Ok(exclusion_checker) => filter_ignored_files(exclusion_checker, paths),
-                Err(_) => {
-                    // We're unable to read the .gitignore file, so we'll silently allow everything.
-                    // Please see discussion: https://github.com/rust-lang/mdBook/pull/1051
-                    paths.iter().map(|path| path.to_path_buf()).collect()
-                }
+            let (ignore, err) = Gitignore::new(&gitignore_path);
+            if let Some(err) = err {
+                warn!(
+                    "error reading gitignore `{}`: {err}",
+                    gitignore_path.display()
+                );
             }
+            filter_ignored_files(ignore, paths)
         }
         None => {
             // There is no .gitignore file.
@@ -85,18 +86,13 @@ fn find_gitignore(book_root: &Path) -> Option<PathBuf> {
         .find(|p| p.exists())
 }
 
-fn filter_ignored_files(exclusion_checker: gitignore::File, paths: &[PathBuf]) -> Vec<PathBuf> {
+fn filter_ignored_files(ignore: Gitignore, paths: &[PathBuf]) -> Vec<PathBuf> {
     paths
         .iter()
-        .filter(|path| match exclusion_checker.is_excluded(path) {
-            Ok(exclude) => !exclude,
-            Err(error) => {
-                warn!(
-                    "Unable to determine if {:?} is excluded: {:?}. Including it.",
-                    &path, error
-                );
-                true
-            }
+        .filter(|path| {
+            !ignore
+                .matched_path_or_any_parents(path, path.is_dir())
+                .is_ignore()
         })
         .map(|path| path.to_path_buf())
         .collect()
diff --git a/vendor/mdbook/src/config.rs b/vendor/mdbook/src/config.rs
index 0c367d848..4641d1a26 100644
--- a/vendor/mdbook/src/config.rs
+++ b/vendor/mdbook/src/config.rs
@@ -308,7 +308,7 @@ impl<'de> serde::Deserialize<'de> for Config {
             warn!("`description` under a table called `[book]`, move the `destination` entry");
             warn!("from `[output.html]`, renamed to `build-dir`, under a table called");
             warn!("`[build]`, and it should all work.");
-            warn!("Documentation: http://rust-lang.github.io/mdBook/format/config.html");
+            warn!("Documentation: https://rust-lang.github.io/mdBook/format/config.html");
             return Ok(Config::from_legacy(raw));
         }
 
@@ -504,6 +504,8 @@ pub struct HtmlConfig {
     /// Playground settings.
     #[serde(alias = "playpen")]
     pub playground: Playground,
+    /// Code settings.
+    pub code: Code,
     /// Print settings.
     pub print: Print,
     /// Don't render section labels.
@@ -556,6 +558,7 @@ impl Default for HtmlConfig {
             additional_js: Vec::new(),
             fold: Fold::default(),
             playground: Playground::default(),
+            code: Code::default(),
             print: Print::default(),
             no_section_label: false,
             search: None,
@@ -642,6 +645,22 @@ impl Default for Playground {
     }
 }
 
+/// Configuration for tweaking how the the HTML renderer handles code blocks.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(default, rename_all = "kebab-case")]
+pub struct Code {
+    /// A prefix string to hide lines per language (one or more chars).
+    pub hidelines: HashMap<String, String>,
+}
+
+impl Default for Code {
+    fn default() -> Code {
+        Code {
+            hidelines: HashMap::new(),
+        }
+    }
+}
+
 /// Configuration of the search functionality of the HTML renderer.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case")]
@@ -703,7 +722,7 @@ trait Updateable<'de>: Serialize + Deserialize<'de> {
         let mut raw = Value::try_from(&self).expect("unreachable");
 
         if let Ok(value) = Value::try_from(value) {
-            let _ = raw.insert(key, value);
+            raw.insert(key, value);
         } else {
             return;
         }
diff --git a/vendor/mdbook/src/preprocess/links.rs b/vendor/mdbook/src/preprocess/links.rs
index c2c81f522..0af211960 100644
--- a/vendor/mdbook/src/preprocess/links.rs
+++ b/vendor/mdbook/src/preprocess/links.rs
@@ -93,7 +93,7 @@ where
     for link in find_links(s) {
         replaced.push_str(&s[previous_end_index..link.start_index]);
 
-        match link.render_with_path(&path, chapter_title) {
+        match link.render_with_path(path, chapter_title) {
             Ok(new_content) => {
                 if depth < MAX_LINK_NESTED_DEPTH {
                     if let Some(rel_path) = link.link_type.relative_path(path) {
@@ -327,7 +327,7 @@ impl<'a> Link<'a> {
         let base = base.as_ref();
         match self.link_type {
             // omit the escape char
-            LinkType::Escaped => Ok((&self.link_text[1..]).to_owned()),
+            LinkType::Escaped => Ok(self.link_text[1..].to_owned()),
             LinkType::Include(ref pat, ref range_or_anchor) => {
                 let target = base.join(pat);
 
diff --git a/vendor/mdbook/src/renderer/html_handlebars/hbs_renderer.rs b/vendor/mdbook/src/renderer/html_handlebars/hbs_renderer.rs
index e170e2fcd..709aa0667 100644
--- a/vendor/mdbook/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/vendor/mdbook/src/renderer/html_handlebars/hbs_renderer.rs
@@ -1,5 +1,5 @@
 use crate::book::{Book, BookItem};
-use crate::config::{BookConfig, Config, HtmlConfig, Playground, RustEdition};
+use crate::config::{BookConfig, Code, Config, HtmlConfig, Playground, RustEdition};
 use crate::errors::*;
 use crate::renderer::html_handlebars::helpers;
 use crate::renderer::{RenderContext, Renderer};
@@ -99,7 +99,7 @@ impl HtmlHandlebars {
         ctx.data.insert("title".to_owned(), json!(title));
         ctx.data.insert(
             "path_to_root".to_owned(),
-            json!(utils::fs::path_to_root(&path)),
+            json!(utils::fs::path_to_root(path)),
         );
         if let Some(ref section) = ch.number {
             ctx.data
@@ -110,7 +110,12 @@ impl HtmlHandlebars {
         debug!("Render template");
         let rendered = ctx.handlebars.render("index", &ctx.data)?;
 
-        let rendered = self.post_process(rendered, &ctx.html_config.playground, ctx.edition);
+        let rendered = self.post_process(
+            rendered,
+            &ctx.html_config.playground,
+            &ctx.html_config.code,
+            ctx.edition,
+        );
 
         // Write to file
         debug!("Creating {}", filepath.display());
@@ -121,8 +126,12 @@ impl HtmlHandlebars {
             ctx.data.insert("path_to_root".to_owned(), json!(""));
             ctx.data.insert("is_index".to_owned(), json!(true));
             let rendered_index = ctx.handlebars.render("index", &ctx.data)?;
-            let rendered_index =
-                self.post_process(rendered_index, &ctx.html_config.playground, ctx.edition);
+            let rendered_index = self.post_process(
+                rendered_index,
+                &ctx.html_config.playground,
+                &ctx.html_config.code,
+                ctx.edition,
+            );
             debug!("Creating index.html from {}", ctx_path);
             utils::fs::write_file(&ctx.destination, "index.html", rendered_index.as_bytes())?;
         }
@@ -182,8 +191,12 @@ impl HtmlHandlebars {
         data_404.insert("title".to_owned(), json!(title));
         let rendered = handlebars.render("index", &data_404)?;
 
-        let rendered =
-            self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
+        let rendered = self.post_process(
+            rendered,
+            &html_config.playground,
+            &html_config.code,
+            ctx.config.rust.edition,
+        );
         let output_file = get_404_output_file(&html_config.input_404);
         utils::fs::write_file(destination, output_file, rendered.as_bytes())?;
         debug!("Creating 404.html ✓");
@@ -195,11 +208,13 @@ impl HtmlHandlebars {
         &self,
         rendered: String,
         playground_config: &Playground,
+        code_config: &Code,
         edition: Option<RustEdition>,
     ) -> String {
         let rendered = build_header_links(&rendered);
         let rendered = fix_code_blocks(&rendered);
         let rendered = add_playground_pre(&rendered, playground_config, edition);
+        let rendered = hide_lines(&rendered, code_config);
 
         rendered
     }
@@ -275,7 +290,8 @@ impl HtmlHandlebars {
             "FontAwesome/fonts/FontAwesome.ttf",
             theme::FONT_AWESOME_TTF,
         )?;
-        if html_config.copy_fonts {
+        // Don't copy the stock fonts if the user has specified their own fonts to use.
+        if html_config.copy_fonts && theme.fonts_css.is_none() {
             write_file(destination, "fonts/fonts.css", theme::fonts::CSS)?;
             for (file_name, contents) in theme::fonts::LICENSES.iter() {
                 write_file(destination, file_name, contents)?;
@@ -291,20 +307,13 @@ impl HtmlHandlebars {
         }
         if let Some(fonts_css) = &theme.fonts_css {
             if !fonts_css.is_empty() {
-                if html_config.copy_fonts {
-                    warn!(
-                        "output.html.copy_fonts is deprecated.\n\
-                        Set copy_fonts=false and ensure the fonts you want are in \
-                        the `theme/fonts/` directory."
-                    );
-                }
-                write_file(destination, "fonts/fonts.css", &fonts_css)?;
+                write_file(destination, "fonts/fonts.css", fonts_css)?;
             }
         }
         if !html_config.copy_fonts && theme.fonts_css.is_none() {
             warn!(
-                "output.html.copy_fonts is deprecated.\n\
-                This book appears to have copy_fonts=false without a fonts.css file.\n\
+                "output.html.copy-fonts is deprecated.\n\
+                This book appears to have copy-fonts=false in book.toml without a fonts.css file.\n\
                 Add an empty `theme/fonts/fonts.css` file to squelch this warning."
             );
         }
@@ -553,7 +562,7 @@ impl Renderer for HtmlHandlebars {
         // Print version
         let mut print_content = String::new();
 
-        fs::create_dir_all(&destination)
+        fs::create_dir_all(destination)
             .with_context(|| "Unexpected error when constructing destination path")?;
 
         let mut is_index = true;
@@ -589,8 +598,12 @@ impl Renderer for HtmlHandlebars {
             debug!("Render template");
             let rendered = handlebars.render("index", &data)?;
 
-            let rendered =
-                self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
+            let rendered = self.post_process(
+                rendered,
+                &html_config.playground,
+                &html_config.code,
+                ctx.config.rust.edition,
+            );
 
             utils::fs::write_file(destination, "print.html", rendered.as_bytes())?;
             debug!("Creating print.html ✓");
@@ -795,8 +808,10 @@ fn make_data(
 /// Goes through the rendered HTML, making sure all header tags have
 /// an anchor respectively so people can link to sections directly.
 fn build_header_links(html: &str) -> String {
-    static BUILD_HEADER_LINKS: Lazy<Regex> =
-        Lazy::new(|| Regex::new(r"<h(\d)>(.*?)</h\d>").unwrap());
+    static BUILD_HEADER_LINKS: Lazy<Regex> = Lazy::new(|| {
+        Regex::new(r#"<h(\d)(?: id="([^"]+)")?(?: class="([^"]+)")?>(.*?)</h\d>"#).unwrap()
+    });
+    static IGNORE_CLASS: &[&str] = &["menu-title"];
 
     let mut id_counter = HashMap::new();
 
@@ -806,7 +821,22 @@ fn build_header_links(html: &str) -> String {
                 .parse()
                 .expect("Regex should ensure we only ever get numbers here");
 
-            insert_link_into_header(level, &caps[2], &mut id_counter)
+            // Ignore .menu-title because now it's getting detected by the regex.
+            if let Some(classes) = caps.get(3) {
+                for class in classes.as_str().split(" ") {
+                    if IGNORE_CLASS.contains(&class) {
+                        return caps[0].to_string();
+                    }
+                }
+            }
+
+            insert_link_into_header(
+                level,
+                &caps[4],
+                caps.get(2).map(|x| x.as_str().to_string()),
+                caps.get(3).map(|x| x.as_str().to_string()),
+                &mut id_counter,
+            )
         })
         .into_owned()
 }
@@ -816,15 +846,21 @@ fn build_header_links(html: &str) -> String {
 fn insert_link_into_header(
     level: usize,
     content: &str,
+    id: Option<String>,
+    classes: Option<String>,
     id_counter: &mut HashMap<String, usize>,
 ) -> String {
-    let id = utils::unique_id_from_content(content, id_counter);
+    let id = id.unwrap_or_else(|| utils::unique_id_from_content(content, id_counter));
+    let classes = classes
+        .map(|s| format!(" class=\"{s}\""))
+        .unwrap_or_default();
 
     format!(
-        r##"<h{level} id="{id}"><a class="header" href="#{id}">{text}</a></h{level}>"##,
+        r##"<h{level} id="{id}"{classes}><a class="header" href="#{id}">{text}</a></h{level}>"##,
         level = level,
         id = id,
-        text = content
+        text = content,
+        classes = classes
     )
 }
 
@@ -856,67 +892,64 @@ fn fix_code_blocks(html: &str) -> String {
         .into_owned()
 }
 
+static CODE_BLOCK_RE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>(.*?)</code>)"##).unwrap());
+
 fn add_playground_pre(
     html: &str,
     playground_config: &Playground,
     edition: Option<RustEdition>,
 ) -> String {
-    static ADD_PLAYGROUND_PRE: Lazy<Regex> =
-        Lazy::new(|| Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>(.*?)</code>)"##).unwrap());
-
-    ADD_PLAYGROUND_PRE
+    CODE_BLOCK_RE
         .replace_all(html, |caps: &Captures<'_>| {
             let text = &caps[1];
             let classes = &caps[2];
             let code = &caps[3];
 
-            if classes.contains("language-rust") {
-                if (!classes.contains("ignore")
+            if classes.contains("language-rust")
+                && ((!classes.contains("ignore")
                     && !classes.contains("noplayground")
                     && !classes.contains("noplaypen")
                     && playground_config.runnable)
-                    || classes.contains("mdbook-runnable")
-                {
-                    let contains_e2015 = classes.contains("edition2015");
-                    let contains_e2018 = classes.contains("edition2018");
-                    let contains_e2021 = classes.contains("edition2021");
-                    let edition_class = if contains_e2015 || contains_e2018 || contains_e2021 {
-                        // the user forced edition, we should not overwrite it
-                        ""
-                    } else {
-                        match edition {
-                            Some(RustEdition::E2015) => " edition2015",
-                            Some(RustEdition::E2018) => " edition2018",
-                            Some(RustEdition::E2021) => " edition2021",
-                            None => "",
-                        }
-                    };
-
-                    // wrap the contents in an external pre block
-                    format!(
-                        "<pre class=\"playground\"><code class=\"{}{}\">{}</code></pre>",
-                        classes,
-                        edition_class,
-                        {
-                            let content: Cow<'_, str> = if playground_config.editable
-                                && classes.contains("editable")
-                                || text.contains("fn main")
-                                || text.contains("quick_main!")
-                            {
-                                code.into()
-                            } else {
-                                // we need to inject our own main
-                                let (attrs, code) = partition_source(code);
-
-                                format!("# #![allow(unused)]\n{}#fn main() {{\n{}#}}", attrs, code)
-                                    .into()
-                            };
-                            hide_lines(&content)
-                        }
-                    )
+                    || classes.contains("mdbook-runnable"))
+            {
+                let contains_e2015 = classes.contains("edition2015");
+                let contains_e2018 = classes.contains("edition2018");
+                let contains_e2021 = classes.contains("edition2021");
+                let edition_class = if contains_e2015 || contains_e2018 || contains_e2021 {
+                    // the user forced edition, we should not overwrite it
+                    ""
                 } else {
-                    format!("<code class=\"{}\">{}</code>", classes, hide_lines(code))
-                }
+                    match edition {
+                        Some(RustEdition::E2015) => " edition2015",
+                        Some(RustEdition::E2018) => " edition2018",
+                        Some(RustEdition::E2021) => " edition2021",
+                        None => "",
+                    }
+                };
+
+                // wrap the contents in an external pre block
+                format!(
+                    "<pre class=\"playground\"><code class=\"{}{}\">{}</code></pre>",
+                    classes,
+                    edition_class,
+                    {
+                        let content: Cow<'_, str> = if playground_config.editable
+                            && classes.contains("editable")
+                            || text.contains("fn main")
+                            || text.contains("quick_main!")
+                        {
+                            code.into()
+                        } else {
+                            // we need to inject our own main
+                            let (attrs, code) = partition_source(code);
+
+                            format!("# #![allow(unused)]\n{}#fn main() {{\n{}#}}", attrs, code)
+                                .into()
+                        };
+                        content
+                    }
+                )
             } else {
                 // not language-rust, so no-op
                 text.to_owned()
@@ -925,7 +958,50 @@ fn add_playground_pre(
         .into_owned()
 }
 
-fn hide_lines(content: &str) -> String {
+/// Modifies all `<code>` blocks to convert "hidden" lines and to wrap them in
+/// a `<span class="boring">`.
+fn hide_lines(html: &str, code_config: &Code) -> String {
+    let language_regex = Regex::new(r"\blanguage-(\w+)\b").unwrap();
+    let hidelines_regex = Regex::new(r"\bhidelines=(\S+)").unwrap();
+    CODE_BLOCK_RE
+        .replace_all(html, |caps: &Captures<'_>| {
+            let text = &caps[1];
+            let classes = &caps[2];
+            let code = &caps[3];
+
+            if classes.contains("language-rust") {
+                format!(
+                    "<code class=\"{}\">{}</code>",
+                    classes,
+                    hide_lines_rust(code)
+                )
+            } else {
+                // First try to get the prefix from the code block
+                let hidelines_capture = hidelines_regex.captures(classes);
+                let hidelines_prefix = match &hidelines_capture {
+                    Some(capture) => Some(&capture[1]),
+                    None => {
+                        // Then look up the prefix by language
+                        language_regex.captures(classes).and_then(|capture| {
+                            code_config.hidelines.get(&capture[1]).map(|p| p.as_str())
+                        })
+                    }
+                };
+
+                match hidelines_prefix {
+                    Some(prefix) => format!(
+                        "<code class=\"{}\">{}</code>",
+                        classes,
+                        hide_lines_with_prefix(code, prefix)
+                    ),
+                    None => text.to_owned(),
+                }
+            }
+        })
+        .into_owned()
+}
+
+fn hide_lines_rust(content: &str) -> String {
     static BORING_LINES_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"^(\s*)#(.?)(.*)$").unwrap());
 
     let mut result = String::with_capacity(content.len());
@@ -958,6 +1034,26 @@ fn hide_lines(content: &str) -> String {
     result
 }
 
+fn hide_lines_with_prefix(content: &str, prefix: &str) -> String {
+    let mut result = String::with_capacity(content.len());
+    for line in content.lines() {
+        if line.trim_start().starts_with(prefix) {
+            let pos = line.find(prefix).unwrap();
+            let (ws, rest) = (&line[..pos], &line[pos + prefix.len()..]);
+
+            result += "<span class=\"boring\">";
+            result += ws;
+            result += rest;
+            result += "\n";
+            result += "</span>";
+            continue;
+        }
+        result += line;
+        result += "\n";
+    }
+    result
+}
+
 fn partition_source(s: &str) -> (String, String) {
     let mut after_header = false;
     let mut before = String::new();
@@ -993,6 +1089,7 @@ struct RenderItemContext<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use pretty_assertions::assert_eq;
 
     #[test]
     fn original_build_header_links() {
@@ -1021,6 +1118,21 @@ mod tests {
                 "<h1>Foo</h1><h3>Foo</h3>",
                 r##"<h1 id="foo"><a class="header" href="#foo">Foo</a></h1><h3 id="foo-1"><a class="header" href="#foo-1">Foo</a></h3>"##,
             ),
+            // id only
+            (
+                r##"<h1 id="foobar">Foo</h1>"##,
+                r##"<h1 id="foobar"><a class="header" href="#foobar">Foo</a></h1>"##,
+            ),
+            // class only
+            (
+                r##"<h1 class="class1 class2">Foo</h1>"##,
+                r##"<h1 id="foo" class="class1 class2"><a class="header" href="#foo">Foo</a></h1>"##,
+            ),
+            // both id and class
+            (
+                r##"<h1 id="foobar" class="class1 class2">Foo</h1>"##,
+                r##"<h1 id="foobar" class="class1 class2"><a class="header" href="#foobar">Foo</a></h1>"##,
+            ),
         ];
 
         for (src, should_be) in inputs {
@@ -1033,17 +1145,17 @@ mod tests {
     fn add_playground() {
         let inputs = [
           ("<code class=\"language-rust\">x()</code>",
-           "<pre class=\"playground\"><code class=\"language-rust\"><span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}</span></code></pre>"),
+           "<pre class=\"playground\"><code class=\"language-rust\"># #![allow(unused)]\n#fn main() {\nx()\n#}</code></pre>"),
           ("<code class=\"language-rust\">fn main() {}</code>",
            "<pre class=\"playground\"><code class=\"language-rust\">fn main() {}</code></pre>"),
           ("<code class=\"language-rust editable\">let s = \"foo\n # bar\n\";</code>",
-           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n<span class=\"boring\"> bar\n</span>\";</code></pre>"),
-          ("<code class=\"language-rust editable\">let s = \"foo\n ## bar\n\";</code>",
            "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n # bar\n\";</code></pre>"),
+          ("<code class=\"language-rust editable\">let s = \"foo\n ## bar\n\";</code>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n ## bar\n\";</code></pre>"),
           ("<code class=\"language-rust editable\">let s = \"foo\n # bar\n#\n\";</code>",
-           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n<span class=\"boring\"> bar\n</span><span class=\"boring\">\n</span>\";</code></pre>"),
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n # bar\n#\n\";</code></pre>"),
           ("<code class=\"language-rust ignore\">let s = \"foo\n # bar\n\";</code>",
-           "<code class=\"language-rust ignore\">let s = \"foo\n<span class=\"boring\"> bar\n</span>\";</code>"),
+           "<code class=\"language-rust ignore\">let s = \"foo\n # bar\n\";</code>"),
           ("<code class=\"language-rust editable\">#![no_std]\nlet s = \"foo\";\n #[some_attr]</code>",
            "<pre class=\"playground\"><code class=\"language-rust editable\">#![no_std]\nlet s = \"foo\";\n #[some_attr]</code></pre>"),
         ];
@@ -1063,7 +1175,7 @@ mod tests {
     fn add_playground_edition2015() {
         let inputs = [
           ("<code class=\"language-rust\">x()</code>",
-           "<pre class=\"playground\"><code class=\"language-rust edition2015\"><span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}</span></code></pre>"),
+           "<pre class=\"playground\"><code class=\"language-rust edition2015\"># #![allow(unused)]\n#fn main() {\nx()\n#}</code></pre>"),
           ("<code class=\"language-rust\">fn main() {}</code>",
            "<pre class=\"playground\"><code class=\"language-rust edition2015\">fn main() {}</code></pre>"),
           ("<code class=\"language-rust edition2015\">fn main() {}</code>",
@@ -1087,7 +1199,7 @@ mod tests {
     fn add_playground_edition2018() {
         let inputs = [
           ("<code class=\"language-rust\">x()</code>",
-           "<pre class=\"playground\"><code class=\"language-rust edition2018\"><span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}</span></code></pre>"),
+           "<pre class=\"playground\"><code class=\"language-rust edition2018\"># #![allow(unused)]\n#fn main() {\nx()\n#}</code></pre>"),
           ("<code class=\"language-rust\">fn main() {}</code>",
            "<pre class=\"playground\"><code class=\"language-rust edition2018\">fn main() {}</code></pre>"),
           ("<code class=\"language-rust edition2015\">fn main() {}</code>",
@@ -1111,7 +1223,7 @@ mod tests {
     fn add_playground_edition2021() {
         let inputs = [
             ("<code class=\"language-rust\">x()</code>",
-             "<pre class=\"playground\"><code class=\"language-rust edition2021\"><span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}</span></code></pre>"),
+             "<pre class=\"playground\"><code class=\"language-rust edition2021\"># #![allow(unused)]\n#fn main() {\nx()\n#}</code></pre>"),
             ("<code class=\"language-rust\">fn main() {}</code>",
              "<pre class=\"playground\"><code class=\"language-rust edition2021\">fn main() {}</code></pre>"),
             ("<code class=\"language-rust edition2015\">fn main() {}</code>",
@@ -1131,4 +1243,60 @@ mod tests {
             assert_eq!(&*got, *should_be);
         }
     }
+
+    #[test]
+    fn hide_lines_language_rust() {
+        let inputs = [
+          (
+           "<pre class=\"playground\"><code class=\"language-rust\">\n# #![allow(unused)]\n#fn main() {\nx()\n#}</code></pre>",
+           "<pre class=\"playground\"><code class=\"language-rust\">\n<span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}</span></code></pre>",),
+          (
+           "<pre class=\"playground\"><code class=\"language-rust\">fn main() {}</code></pre>",
+           "<pre class=\"playground\"><code class=\"language-rust\">fn main() {}</code></pre>",),
+          (
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n # bar\n\";</code></pre>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n<span class=\"boring\"> bar\n</span>\";</code></pre>",),
+          (
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n ## bar\n\";</code></pre>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n # bar\n\";</code></pre>",),
+          (
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n # bar\n#\n\";</code></pre>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n<span class=\"boring\"> bar\n</span><span class=\"boring\">\n</span>\";</code></pre>",),
+          (
+           "<code class=\"language-rust ignore\">let s = \"foo\n # bar\n\";</code>",
+           "<code class=\"language-rust ignore\">let s = \"foo\n<span class=\"boring\"> bar\n</span>\";</code>",),
+          (
+           "<pre class=\"playground\"><code class=\"language-rust editable\">#![no_std]\nlet s = \"foo\";\n #[some_attr]</code></pre>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">#![no_std]\nlet s = \"foo\";\n #[some_attr]</code></pre>",),
+        ];
+        for (src, should_be) in &inputs {
+            let got = hide_lines(src, &Code::default());
+            assert_eq!(&*got, *should_be);
+        }
+    }
+
+    #[test]
+    fn hide_lines_language_other() {
+        let inputs = [
+          (
+           "<code class=\"language-python\">~hidden()\nnothidden():\n~    hidden()\n    ~hidden()\n    nothidden()</code>",
+           "<code class=\"language-python\"><span class=\"boring\">hidden()\n</span>nothidden():\n<span class=\"boring\">    hidden()\n</span><span class=\"boring\">    hidden()\n</span>    nothidden()\n</code>",),
+           (
+            "<code class=\"language-python hidelines=!!!\">!!!hidden()\nnothidden():\n!!!    hidden()\n    !!!hidden()\n    nothidden()</code>",
+            "<code class=\"language-python hidelines=!!!\"><span class=\"boring\">hidden()\n</span>nothidden():\n<span class=\"boring\">    hidden()\n</span><span class=\"boring\">    hidden()\n</span>    nothidden()\n</code>",),
+        ];
+        for (src, should_be) in &inputs {
+            let got = hide_lines(
+                src,
+                &Code {
+                    hidelines: {
+                        let mut map = HashMap::new();
+                        map.insert("python".to_string(), "~".to_string());
+                        map
+                    },
+                },
+            );
+            assert_eq!(&*got, *should_be);
+        }
+    }
 }
diff --git a/vendor/mdbook/src/renderer/html_handlebars/helpers/navigation.rs b/vendor/mdbook/src/renderer/html_handlebars/helpers/navigation.rs
index b184c4410..968a67016 100644
--- a/vendor/mdbook/src/renderer/html_handlebars/helpers/navigation.rs
+++ b/vendor/mdbook/src/renderer/html_handlebars/helpers/navigation.rs
@@ -127,7 +127,7 @@ fn render(
 
     context.insert(
         "path_to_root".to_owned(),
-        json!(utils::fs::path_to_root(&base_path)),
+        json!(utils::fs::path_to_root(base_path)),
     );
 
     chapter
diff --git a/vendor/mdbook/src/renderer/html_handlebars/search.rs b/vendor/mdbook/src/renderer/html_handlebars/search.rs
index a9e2f5ca6..24d62fda2 100644
--- a/vendor/mdbook/src/renderer/html_handlebars/search.rs
+++ b/vendor/mdbook/src/renderer/html_handlebars/search.rs
@@ -138,9 +138,11 @@ fn render_item(
 
                 in_heading = true;
             }
-            Event::End(Tag::Heading(i, ..)) if i as u32 <= max_section_depth => {
+            Event::End(Tag::Heading(i, id, _classes)) if i as u32 <= max_section_depth => {
                 in_heading = false;
-                section_id = Some(utils::unique_id_from_content(&heading, &mut id_counter));
+                section_id = id
+                    .map(|id| id.to_string())
+                    .or_else(|| Some(utils::unique_id_from_content(&heading, &mut id_counter)));
                 breadcrumbs.push(heading.clone());
             }
             Event::Start(Tag::FootnoteDefinition(name)) => {
diff --git a/vendor/mdbook/src/renderer/markdown_renderer.rs b/vendor/mdbook/src/renderer/markdown_renderer.rs
index 13bd05cc3..4a5a5c2af 100644
--- a/vendor/mdbook/src/renderer/markdown_renderer.rs
+++ b/vendor/mdbook/src/renderer/markdown_renderer.rs
@@ -37,14 +37,14 @@ impl Renderer for MarkdownRenderer {
                 if !ch.is_draft_chapter() {
                     utils::fs::write_file(
                         &ctx.destination,
-                        &ch.path.as_ref().expect("Checked path exists before"),
+                        ch.path.as_ref().expect("Checked path exists before"),
                         ch.content.as_bytes(),
                     )?;
                 }
             }
         }
 
-        fs::create_dir_all(&destination)
+        fs::create_dir_all(destination)
             .with_context(|| "Unexpected error when constructing destination path")?;
 
         Ok(())
diff --git a/vendor/mdbook/src/theme/book.js b/vendor/mdbook/src/theme/book.js
index e303ebb45..67a8a5b08 100644
--- a/vendor/mdbook/src/theme/book.js
+++ b/vendor/mdbook/src/theme/book.js
@@ -68,7 +68,7 @@ function playground_text(playground, hidden = true) {
     }
 
     // updates the visibility of play button based on `no_run` class and
-    // used crates vs ones available on http://play.rust-lang.org
+    // used crates vs ones available on https://play.rust-lang.org
     function update_play_button(pre_block, playground_crates) {
         var play_button = pre_block.querySelector(".play-button");
 
@@ -179,7 +179,7 @@ function playground_text(playground, hidden = true) {
     // even if highlighting doesn't apply
     code_nodes.forEach(function (block) { block.classList.add('hljs'); });
 
-    Array.from(document.querySelectorAll("code.language-rust")).forEach(function (block) {
+    Array.from(document.querySelectorAll("code.hljs")).forEach(function (block) {
 
         var lines = Array.from(block.querySelectorAll('.boring'));
         // If no lines were hidden, return
@@ -551,13 +551,6 @@ function playground_text(playground, hidden = true) {
             firstContact = null;
         }
     }, { passive: true });
-
-    // Scroll sidebar to current active section
-    var activeSection = document.getElementById("sidebar").querySelector(".active");
-    if (activeSection) {
-        // https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
-        activeSection.scrollIntoView({ block: 'center' });
-    }
 })();
 
 (function chapterNavigation() {
@@ -676,13 +669,14 @@ function playground_text(playground, hidden = true) {
         }, { passive: true });
     })();
     (function controllBorder() {
-        menu.classList.remove('bordered');
-        document.addEventListener('scroll', function () {
+        function updateBorder() {
             if (menu.offsetTop === 0) {
                 menu.classList.remove('bordered');
             } else {
                 menu.classList.add('bordered');
             }
-        }, { passive: true });
+        }
+        updateBorder();
+        document.addEventListener('scroll', updateBorder, { passive: true });
     })();
 })();
diff --git a/vendor/mdbook/src/theme/index.hbs b/vendor/mdbook/src/theme/index.hbs
index 6f3948c65..80315c48f 100644
--- a/vendor/mdbook/src/theme/index.hbs
+++ b/vendor/mdbook/src/theme/index.hbs
@@ -110,12 +110,34 @@
             <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
         </nav>
 
+        <!-- Track and set sidebar scroll position -->
+        <script>
+            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
+            sidebarScrollbox.addEventListener('click', function(e) {
+                if (e.target.tagName === 'A') {
+                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
+                }
+            }, { passive: true });
+            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
+            sessionStorage.removeItem('sidebar-scroll');
+            if (sidebarScrollTop) {
+                // preserve sidebar scroll position when navigating via links within sidebar
+                sidebarScrollbox.scrollTop = sidebarScrollTop;
+            } else {
+                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
+                var activeSection = document.querySelector('#sidebar .active');
+                if (activeSection) {
+                    activeSection.scrollIntoView({ block: 'center' });
+                }
+            }
+        </script>
+
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
                 {{> header}}
                 <div id="menu-bar-hover-placeholder"></div>
-                <div id="menu-bar" class="menu-bar sticky bordered">
+                <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
                             <i class="fa fa-bars"></i>
diff --git a/vendor/mdbook/src/theme/tomorrow-night.css b/vendor/mdbook/src/theme/tomorrow-night.css
index 5b4aca77c..81fe276e7 100644
--- a/vendor/mdbook/src/theme/tomorrow-night.css
+++ b/vendor/mdbook/src/theme/tomorrow-night.css
@@ -1,7 +1,7 @@
 /* Tomorrow Night Theme */
-/* http://jmblog.github.com/color-themes-for-google-code-highlightjs */
+/* https://github.com/jmblog/color-themes-for-highlightjs */
 /* Original theme - https://github.com/chriskempson/tomorrow-theme */
-/* http://jmblog.github.com/color-themes-for-google-code-highlightjs */
+/* https://github.com/jmblog/color-themes-for-highlightjs */
 
 /* Tomorrow Comment */
 .hljs-comment {
diff --git a/vendor/mdbook/src/utils/fs.rs b/vendor/mdbook/src/utils/fs.rs
index 67f7062db..8ad5aad8b 100644
--- a/vendor/mdbook/src/utils/fs.rs
+++ b/vendor/mdbook/src/utils/fs.rs
@@ -210,39 +210,36 @@ mod tests {
         };
 
         // Create a couple of files
-        if let Err(err) = fs::File::create(&tmp.path().join("file.txt")) {
+        if let Err(err) = fs::File::create(tmp.path().join("file.txt")) {
             panic!("Could not create file.txt: {}", err);
         }
-        if let Err(err) = fs::File::create(&tmp.path().join("file.md")) {
+        if let Err(err) = fs::File::create(tmp.path().join("file.md")) {
             panic!("Could not create file.md: {}", err);
         }
-        if let Err(err) = fs::File::create(&tmp.path().join("file.png")) {
+        if let Err(err) = fs::File::create(tmp.path().join("file.png")) {
             panic!("Could not create file.png: {}", err);
         }
-        if let Err(err) = fs::create_dir(&tmp.path().join("sub_dir")) {
+        if let Err(err) = fs::create_dir(tmp.path().join("sub_dir")) {
             panic!("Could not create sub_dir: {}", err);
         }
-        if let Err(err) = fs::File::create(&tmp.path().join("sub_dir/file.png")) {
+        if let Err(err) = fs::File::create(tmp.path().join("sub_dir/file.png")) {
             panic!("Could not create sub_dir/file.png: {}", err);
         }
-        if let Err(err) = fs::create_dir(&tmp.path().join("sub_dir_exists")) {
+        if let Err(err) = fs::create_dir(tmp.path().join("sub_dir_exists")) {
             panic!("Could not create sub_dir_exists: {}", err);
         }
-        if let Err(err) = fs::File::create(&tmp.path().join("sub_dir_exists/file.txt")) {
+        if let Err(err) = fs::File::create(tmp.path().join("sub_dir_exists/file.txt")) {
             panic!("Could not create sub_dir_exists/file.txt: {}", err);
         }
-        if let Err(err) = symlink(
-            &tmp.path().join("file.png"),
-            &tmp.path().join("symlink.png"),
-        ) {
+        if let Err(err) = symlink(tmp.path().join("file.png"), tmp.path().join("symlink.png")) {
             panic!("Could not symlink file.png: {}", err);
         }
 
         // Create output dir
-        if let Err(err) = fs::create_dir(&tmp.path().join("output")) {
+        if let Err(err) = fs::create_dir(tmp.path().join("output")) {
             panic!("Could not create output: {}", err);
         }
-        if let Err(err) = fs::create_dir(&tmp.path().join("output/sub_dir_exists")) {
+        if let Err(err) = fs::create_dir(tmp.path().join("output/sub_dir_exists")) {
             panic!("Could not create output/sub_dir_exists: {}", err);
         }
 
@@ -253,22 +250,22 @@ mod tests {
         }
 
         // Check if the correct files where created
-        if !(&tmp.path().join("output/file.txt")).exists() {
+        if !tmp.path().join("output/file.txt").exists() {
             panic!("output/file.txt should exist")
         }
-        if (&tmp.path().join("output/file.md")).exists() {
+        if tmp.path().join("output/file.md").exists() {
             panic!("output/file.md should not exist")
         }
-        if !(&tmp.path().join("output/file.png")).exists() {
+        if !tmp.path().join("output/file.png").exists() {
             panic!("output/file.png should exist")
         }
-        if !(&tmp.path().join("output/sub_dir/file.png")).exists() {
+        if !tmp.path().join("output/sub_dir/file.png").exists() {
             panic!("output/sub_dir/file.png should exist")
         }
-        if !(&tmp.path().join("output/sub_dir_exists/file.txt")).exists() {
+        if !tmp.path().join("output/sub_dir_exists/file.txt").exists() {
             panic!("output/sub_dir/file.png should exist")
         }
-        if !(&tmp.path().join("output/symlink.png")).exists() {
+        if !tmp.path().join("output/symlink.png").exists() {
             panic!("output/symlink.png should exist")
         }
     }
diff --git a/vendor/mdbook/src/utils/mod.rs b/vendor/mdbook/src/utils/mod.rs
index 9f67deda7..9156916ea 100644
--- a/vendor/mdbook/src/utils/mod.rs
+++ b/vendor/mdbook/src/utils/mod.rs
@@ -183,6 +183,7 @@ pub fn new_cmark_parser(text: &str, curly_quotes: bool) -> Parser<'_, '_> {
     opts.insert(Options::ENABLE_FOOTNOTES);
     opts.insert(Options::ENABLE_STRIKETHROUGH);
     opts.insert(Options::ENABLE_TASKLISTS);
+    opts.insert(Options::ENABLE_HEADING_ATTRIBUTES);
     if curly_quotes {
         opts.insert(Options::ENABLE_SMART_PUNCTUATION);
     }