Merge pull request #2312 from ehuss/bump-version

Update to 0.4.37

.github/workflows/main.yml

@@ -1,7 +1,5 @@
 name: CI
 on:
-  push:
-    branches-ignore: [master]
   pull_request:
   merge_group:
 
@@ -31,7 +29,7 @@ jobs:
           - build: msrv
             os: ubuntu-20.04
             # sync MSRV with docs: guide/src/guide/installation.md and Cargo.toml
-            rust: 1.66.0
+            rust: 1.71.0
     steps:
     - uses: actions/checkout@v3
     - name: Install Rust
@@ -49,3 +47,20 @@ jobs:
     - name: Install Rust
       run: rustup update stable && rustup default stable && rustup component add rustfmt
     - run: cargo fmt --check
+
+  # The success job is here to consolidate the total success/failure state of
+  # all other jobs. This job is then included in the GitHub branch protection
+  # rule which prevents merges unless all other jobs are passing. This makes
+  # it easier to manage the list of jobs via this yml file and to prevent
+  # accidentally adding new jobs without also updating the branch protections.
+  success:
+    name: Success gate
+    if: always()
+    needs:
+      - test
+      - rustfmt
+    runs-on: ubuntu-latest
+    steps:
+      - run: jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
+      - name: Done
+        run: exit 0

CHANGELOG.md

@@ -1,5 +1,91 @@
 # Changelog
 
+## mdBook 0.4.37
+[v0.4.36...v0.4.37](https://github.com/rust-lang/mdBook/compare/v0.4.36...v0.4.37)
+
+### Changed
+- ❗️ Updated the markdown parser. This brings in many changes to more closely follow the CommonMark spec. This may cause some small rendering changes. It is recommended to compare the output of the old and new version to check for changes. See <https://github.com/raphlinus/pulldown-cmark/releases/tag/v0.10.0> for more information.
+  [#2308](https://github.com/rust-lang/mdBook/pull/2308)
+- The warning about the legacy `src/theme` directory has been removed.
+  [#2263](https://github.com/rust-lang/mdBook/pull/2263)
+- Updated dependencies. MSRV raised to 1.71.0.
+  [#2283](https://github.com/rust-lang/mdBook/pull/2283)
+  [#2293](https://github.com/rust-lang/mdBook/pull/2293)
+  [#2297](https://github.com/rust-lang/mdBook/pull/2297)
+  [#2310](https://github.com/rust-lang/mdBook/pull/2310)
+  [#2309](https://github.com/rust-lang/mdBook/pull/2309)
+- Some internal performance/memory improvements.
+  [#2273](https://github.com/rust-lang/mdBook/pull/2273)
+  [#2290](https://github.com/rust-lang/mdBook/pull/2290)
+- Made the `pathdiff` dependency optional based on the `watch` feature.
+  [#2291](https://github.com/rust-lang/mdBook/pull/2291)
+
+### Fixed
+- The `s` shortcut key handler should not trigger when focus is in an HTML form.
+  [#2311](https://github.com/rust-lang/mdBook/pull/2311)
+
+## mdBook 0.4.36
+[v0.4.35...v0.4.36](https://github.com/rust-lang/mdBook/compare/v0.4.35...v0.4.36)
+
+### Added
+- Added Nim to the default highlighted languages.
+  [#2232](https://github.com/rust-lang/mdBook/pull/2232)
+- Added a small indicator for the sidebar resize handle.
+  [#2209](https://github.com/rust-lang/mdBook/pull/2209)
+
+### Changed
+- Updated dependencies. MSRV raised to 1.70.0.
+  [#2173](https://github.com/rust-lang/mdBook/pull/2173)
+  [#2250](https://github.com/rust-lang/mdBook/pull/2250)
+  [#2252](https://github.com/rust-lang/mdBook/pull/2252)
+
+### Fixed
+- Fixed blank column in print page when the sidebar was visible.
+  [#2235](https://github.com/rust-lang/mdBook/pull/2235)
+- Fixed indentation of code blocks when Javascript is disabled.
+  [#2162](https://github.com/rust-lang/mdBook/pull/2162)
+- Fixed a panic when `mdbook serve` or `mdbook watch` were given certain kinds of paths.
+  [#2229](https://github.com/rust-lang/mdBook/pull/2229)
+
+## mdBook 0.4.35
+[v0.4.34...v0.4.35](https://github.com/rust-lang/mdBook/compare/v0.4.34...v0.4.35)
+
+### Added
+- Added the `book.text-direction` setting for explicit support for right-to-left languages.
+  [#1641](https://github.com/rust-lang/mdBook/pull/1641)
+- Added `rel=prefetch` to the "next" links to potentially improve browser performance.
+  [#2168](https://github.com/rust-lang/mdBook/pull/2168)
+- Added a `.warning` CSS class which is styled for displaying warning blocks.
+  [#2187](https://github.com/rust-lang/mdBook/pull/2187)
+
+### Changed
+- Better support of the sidebar when JavaScript is disabled.
+  [#2175](https://github.com/rust-lang/mdBook/pull/2175)
+
+## mdBook 0.4.34
+[v0.4.33...v0.4.34](https://github.com/rust-lang/mdBook/compare/v0.4.33...v0.4.34)
+
+### Fixed
+- Fixed file change watcher failing on macOS with a large number of files.
+  [#2157](https://github.com/rust-lang/mdBook/pull/2157)
+
+## mdBook 0.4.33
+[v0.4.32...v0.4.33](https://github.com/rust-lang/mdBook/compare/v0.4.32...v0.4.33)
+
+### Added
+- The `color-scheme` CSS property is now set based on the light/dark theme, which applies some slight color differences in browser elements like scroll bars on some browsers.
+  [#2134](https://github.com/rust-lang/mdBook/pull/2134)
+
+### Fixed
+- Fixed watching of extra-watch-dirs when not running in the book root directory.
+  [#2146](https://github.com/rust-lang/mdBook/pull/2146)
+- Reverted the dependency update to the `toml` crate (again!). This was an unintentional breaking change in 0.4.32.
+  [#2021](https://github.com/rust-lang/mdBook/pull/2021)
+- Changed macOS change notifications to use the kqueue implementation which should fix some issues with repeated rebuilds when a file changed.
+  [#2152](https://github.com/rust-lang/mdBook/pull/2152)
+- Don't set a background color in the print page for code blocks in a header.
+  [#2150](https://github.com/rust-lang/mdBook/pull/2150)
+
 ## mdBook 0.4.32
 [v0.4.31...v0.4.32](https://github.com/rust-lang/mdBook/compare/v0.4.31...v0.4.32)
 
@@ -240,7 +326,7 @@
   [#1771](https://github.com/rust-lang/mdBook/pull/1771)
 - The 404 not-found page now includes the books title in the HTML title tag.
   [#1693](https://github.com/rust-lang/mdBook/pull/1693)
-- Migrated to clap 3.0 which which handles CLI option parsing.
+- Migrated to clap 3.0 which handles CLI option parsing.
   [#1731](https://github.com/rust-lang/mdBook/pull/1731)
 
 ### Fixed

CONTRIBUTING.md

@@ -148,7 +148,7 @@ The following are instructions for updating [highlight.js](https://highlightjs.o
 1. Clone the repository at <https://github.com/highlightjs/highlight.js>
 1. Check out a tagged release (like `10.1.1`).
 1. Run `npm install`
-1. Run `node tools/build.js :common apache armasm coffeescript d handlebars haskell http julia nginx properties r scala x86asm yaml`
+1. Run `node tools/build.js :common apache armasm coffeescript d handlebars haskell http julia nginx nim properties r scala x86asm yaml`
 1. Compare the language list that it spits out to the one in [`syntax-highlighting.md`](https://github.com/camelid/mdBook/blob/master/guide/src/format/theme/syntax-highlighting.md). If any are missing, add them to the list and rebuild (and update these docs). If any are added to the common set, add them to `syntax-highlighting.md`.
 1. Copy `build/highlight.min.js` to mdbook's directory [`highlight.js`](https://github.com/rust-lang/mdBook/blob/master/src/theme/highlight.js).
 1. Be sure to check the highlight.js [CHANGES](https://github.com/highlightjs/highlight.js/blob/main/CHANGES.md) for any breaking changes. Breaking changes that would affect users will need to wait until the next major release.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mdbook"
-version = "0.4.32"
+version = "0.4.37"
 authors = [
     "Mathieu David <mathieudavid@mathieudavid.org>",
     "Michael-F-Bryan <michaelfbryan@gmail.com>",
@@ -14,7 +14,7 @@ license = "MPL-2.0"
 readme = "README.md"
 repository = "https://github.com/rust-lang/mdBook"
 description = "Creates a book from markdown files"
-rust-version = "1.66"
+rust-version = "1.71"
 
 [dependencies]
 anyhow = "1.0.71"
@@ -22,29 +22,30 @@ chrono = { version = "0.4.24", default-features = false, features = ["clock"] }
 clap = { version = "4.3.12", features = ["cargo", "wrap_help"] }
 clap_complete = "4.3.2"
 once_cell = "1.17.1"
-env_logger = "0.10.0"
-handlebars = "4.3.7"
+env_logger = "0.11.1"
+handlebars = "5.0"
 log = "0.4.17"
 memchr = "2.5.0"
 opener = "0.6.1"
-pulldown-cmark = { version = "0.9.3", default-features = false }
+pulldown-cmark = { version = "0.10.0", default-features = false, features = ["html"] }
 regex = "1.8.1"
 serde = { version = "1.0.163", features = ["derive"] }
 serde_json = "1.0.96"
-shlex = "1.1.0"
+shlex = "1.3.0"
 tempfile = "3.4.0"
-toml = "0.7.6"
+toml = "0.5.11" # Do not update, see https://github.com/rust-lang/mdBook/issues/2037
 topological-sort = "0.2.2"
 
 # Watch feature
-notify = { version = "6.0.1", optional = true }
-notify-debouncer-mini = { version = "0.3.0", optional = true }
+notify = { version = "6.1.1", optional = true }
+notify-debouncer-mini = { version = "0.4.1", optional = true }
 ignore = { version = "0.4.20", optional = true }
+pathdiff = { version = "0.2.1", optional = true }
 
 # Serve feature
 futures-util = { version = "0.3.28", optional = true }
 tokio = { version = "1.28.1", features = ["macros", "rt-multi-thread"], optional = true }
-warp = { version = "0.3.5", default-features = false, features = ["websocket"], optional = true }
+warp = { version = "0.3.6", default-features = false, features = ["websocket"], optional = true }
 
 # Search feature
 elasticlunr-rs = { version = "3.0.2", optional = true }
@@ -60,7 +61,7 @@ walkdir = "2.3.3"
 
 [features]
 default = ["watch", "serve", "search"]
-watch = ["dep:notify", "dep:notify-debouncer-mini", "dep:ignore"]
+watch = ["dep:notify", "dep:notify-debouncer-mini", "dep:ignore", "dep:pathdiff"]
 serve = ["dep:futures-util", "dep:tokio", "dep:warp"]
 search = ["dep:elasticlunr-rs", "dep:ammonia"]
 

guide/src/cli/build.md

@@ -7,8 +7,8 @@ mdbook build
 ```
 
 It will try to parse your `SUMMARY.md` file to understand the structure of your
-book and fetch the corresponding files. Note that files mentioned in `SUMMARY.md`
-but not present will be created.
+book and fetch the corresponding files. Note that this will also create files
+mentioned in `SUMMARY.md` which are not yet present.
 
 The rendered output will maintain the same directory structure as the source for
 convenience. Large books will therefore remain structured when rendered.

guide/src/cli/test.md

@@ -6,8 +6,7 @@ of code examples that could get outdated. Therefore it is very important for
 them to be able to automatically test these code examples.
 
 mdBook supports a `test` command that will run all available tests in a book. At
-the moment, only rustdoc tests are supported, but this may be expanded upon in
-the future.
+the moment, only Rust tests are supported.
 
 #### Disable tests on a code block
 
@@ -65,4 +64,4 @@ not specified it will default to the value of the `build.build-dir` key in
 #### --chapter
 
 The `--chapter` (`-c`) option allows you to test a specific chapter of the
-book using the chapter name or the relative path to the chapter.
+book using the chapter name or the relative path to the chapter.

guide/src/continuous-integration.md

@@ -21,7 +21,7 @@ A simple approach would be to use the popular `curl` CLI tool to download the ex
 
 ```sh
 mkdir bin
-curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.32/mdbook-v0.4.32-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=bin
+curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.37/mdbook-v0.4.37-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=bin
 bin/mdbook build
 ```
 

guide/src/for_developers/backends.md

@@ -287,7 +287,7 @@ like this:
 +             if cfg.deny_odds && num_words % 2 == 1 {
 +               eprintln!("{} has an odd number of words!", ch.name);
 +               process::exit(1);
-              }
++             }
           }
       }
   }

guide/src/format/configuration/general.md

@@ -46,6 +46,9 @@ This is general information about your book.
   `src` directly under the root folder. But this is configurable with the `src`
   key in the configuration file.
 - **language:** The main language of the book, which is used as a language attribute `<html lang="en">` for example.
+  This is also used to derive the direction of text (RTL, LTR) within the book.
+- **text-direction**: The direction of text in the book: Left-to-right (LTR) or Right-to-left (RTL). Possible values: `ltr`, `rtl`.
+  When not specified, the text direction is derived from the book's `language` attribute.
 
 **book.toml**
 ```toml
@@ -55,6 +58,7 @@ authors = ["John Doe", "Jane Doe"]
 description = "The example book covers examples."
 src = "my-src"  # the source files will be found in `root/my-src` instead of `root/src`
 language = "en"
+text-direction = "ltr"
 ```
 
 ### Rust options
@@ -97,7 +101,7 @@ extra-watch-dirs = []             # directories to watch for triggering builds
   will be created when the book is built (i.e. `create-missing = true`). If this
   is `false` then the build process will instead exit with an error if any files
   do not exist.
-- **use-default-preprocessors:** Disable the default preprocessors of (`links` &
+- **use-default-preprocessors:** Disable the default preprocessors (of `links` &
   `index`) by setting this option to `false`.
 
   If you have the same, and/or other preprocessors declared via their table
@@ -111,4 +115,4 @@ extra-watch-dirs = []             # directories to watch for triggering builds
     `use-default-preprocessors` that `links` it will run.
 - **extra-watch-dirs**: A list of paths to directories that will be watched in
   the `watch` and `serve` commands. Changes to files under these directories will
-  trigger rebuilds. Useful if your book depends on files outside its `src` directory.
+  trigger rebuilds. Useful if your book depends on files outside its `src` directory.

guide/src/format/markdown.md

@@ -73,14 +73,14 @@ Linking to a URL or local file is easy:
 ```markdown
 Use [mdBook](https://github.com/rust-lang/mdBook). 
 
-Read about [mdBook](mdBook.md).
+Read about [mdBook](mdbook.md).
 
 A bare url: <https://www.rust-lang.org>.
 ```
 
 Use [mdBook](https://github.com/rust-lang/mdBook). 
 
-Read about [mdBook](mdBook.md).
+Read about [mdBook](mdbook.md).
 
 A bare url: <https://www.rust-lang.org>.
 
@@ -232,4 +232,4 @@ Example:
 
 This makes the level 1 heading with the content `Example heading`, ID `first`, and classes `class1` and `class2`. Note that the attributes should be space-separated.
 
-More information can be found in the [heading attrs spec page](https://github.com/raphlinus/pulldown-cmark/blob/master/specs/heading_attrs.txt).
+More information can be found in the [heading attrs spec page](https://github.com/raphlinus/pulldown-cmark/blob/master/pulldown-cmark/specs/heading_attrs.txt).

guide/src/format/mdbook.md

@@ -314,3 +314,51 @@ contents (sidebar) by including a `\{{#title ...}}` near the top of the page.
 ```hbs
 \{{#title My Title}}
 ```
+
+## HTML classes provided by mdBook
+
+<img class="right" src="images/rust-logo-blk.svg" alt="The Rust logo">
+
+### `class="left"` and `"right"`
+
+These classes are provided by default, for inline HTML to float images.
+
+```html
+<img class="right" src="images/rust-logo-blk.svg" alt="The Rust logo">
+```
+
+### `class="hidden"`
+
+HTML tags with class `hidden` will not be shown.
+
+```html
+<div class="hidden">This will not be seen.</div>
+```
+
+<div class="hidden">This will not be seen.</div>
+
+### `class="warning"`
+
+To make a warning or similar note stand out, wrap it in a warning div.
+
+```html
+<div class="warning">
+
+This is a bad thing that you should pay attention to.
+
+Warning blocks should be used sparingly in documentation, to avoid "warning
+fatigue," where people are trained to ignore them because they usually don't
+matter for what they're doing.
+
+</div>
+```
+
+<div class="warning">
+
+This is a bad thing that you should pay attention to.
+
+Warning blocks should be used sparingly in documentation, to avoid "warning
+fatigue," where people are trained to ignore them because they usually don't
+matter for what they're doing.
+
+</div>

guide/src/format/summary.md

@@ -29,11 +29,12 @@ to be ignored at best, or may cause an error when attempting to build the book.
    - [First Chapter](relative/path/to/markdown2.md)
    ```
 
-1. ***Part Title*** - Headers can be used as a title for the following numbered
-   chapters. This can be used to logically separate different sections
-   of the book. The title is rendered as unclickable text.
-   Titles are optional, and the numbered chapters can be broken into as many
-   parts as desired.
+1. ***Part Title*** -
+   Level 1 headers can be used as a title for the following numbered chapters.
+   This can be used to logically separate different sections of the book.
+   The title is rendered as unclickable text.
+   Titles are optional, and the numbered chapters can be broken into as many parts as desired.
+   Part titles must be h1 headers (one `#`), other heading levels are ignored.
    ```markdown
    # My Part Title
 

guide/src/format/theme/syntax-highlighting.md

@@ -44,6 +44,7 @@ your own `highlight.js` file:
 - makefile
 - markdown
 - nginx
+- nim
 - objectivec
 - perl
 - php

guide/src/guide/installation.md

@@ -20,7 +20,7 @@ To make it easier to run, put the path to the binary into your `PATH`.
 
 To build the `mdbook` executable from source, you will first need to install Rust and Cargo.
 Follow the instructions on the [Rust installation page].
-mdBook currently requires at least Rust version 1.66.
+mdBook currently requires at least Rust version 1.71.
 
 Once you have installed Rust, the following command can be used to build and install mdBook:
 

src/book/init.rs

@@ -99,11 +99,12 @@ impl BookBuilder {
     fn write_book_toml(&self) -> Result<()> {
         debug!("Writing book.toml");
         let book_toml = self.root.join("book.toml");
-        let cfg =
-            toml::to_string(&self.config).with_context(|| "Unable to serialize the config")?;
+        let cfg = toml::to_vec(&self.config).with_context(|| "Unable to serialize the config")?;
 
-        fs::write(&book_toml, cfg)
-            .with_context(|| format!("failed to write {}", book_toml.display()))?;
+        File::create(book_toml)
+            .with_context(|| "Couldn't create book.toml")?
+            .write_all(&cfg)
+            .with_context(|| "Unable to write config to book.toml")?;
         Ok(())
     }
 

src/book/summary.rs

@@ -1,7 +1,7 @@
 use crate::errors::*;
 use log::{debug, trace, warn};
-use memchr::{self, Memchr};
-use pulldown_cmark::{self, Event, HeadingLevel, Tag};
+use memchr::Memchr;
+use pulldown_cmark::{DefaultBrokenLinkCallback, Event, HeadingLevel, Tag, TagEnd};
 use serde::{Deserialize, Serialize};
 use std::fmt::{self, Display, Formatter};
 use std::iter::FromIterator;
@@ -163,7 +163,7 @@ impl From<Link> for SummaryItem {
 /// > match the following regex: "[^<>\n[]]+".
 struct SummaryParser<'a> {
     src: &'a str,
-    stream: pulldown_cmark::OffsetIter<'a, 'a>,
+    stream: pulldown_cmark::OffsetIter<'a, DefaultBrokenLinkCallback>,
     offset: usize,
 
     /// We can't actually put an event back into the `OffsetIter` stream, so instead we store it
@@ -210,7 +210,7 @@ macro_rules! collect_events {
 }
 
 impl<'a> SummaryParser<'a> {
-    fn new(text: &str) -> SummaryParser<'_> {
+    fn new(text: &'a str) -> SummaryParser<'a> {
         let pulldown_parser = pulldown_cmark::Parser::new(text).into_offset_iter();
 
         SummaryParser {
@@ -265,7 +265,12 @@ impl<'a> SummaryParser<'a> {
         loop {
             match self.next_event() {
                 Some(ev @ Event::Start(Tag::List(..)))
-                | Some(ev @ Event::Start(Tag::Heading(HeadingLevel::H1, ..))) => {
+                | Some(
+                    ev @ Event::Start(Tag::Heading {
+                        level: HeadingLevel::H1,
+                        ..
+                    }),
+                ) => {
                     if is_prefix {
                         // we've finished prefix chapters and are at the start
                         // of the numbered section.
@@ -275,8 +280,8 @@ impl<'a> SummaryParser<'a> {
                         bail!(self.parse_error("Suffix chapters cannot be followed by a list"));
                     }
                 }
-                Some(Event::Start(Tag::Link(_type, href, _title))) => {
-                    let link = self.parse_link(href.to_string());
+                Some(Event::Start(Tag::Link { dest_url, .. })) => {
+                    let link = self.parse_link(dest_url.to_string());
                     items.push(SummaryItem::Link(link));
                 }
                 Some(Event::Rule) => items.push(SummaryItem::Separator),
@@ -304,10 +309,13 @@ impl<'a> SummaryParser<'a> {
                     break;
                 }
 
-                Some(Event::Start(Tag::Heading(HeadingLevel::H1, ..))) => {
+                Some(Event::Start(Tag::Heading {
+                    level: HeadingLevel::H1,
+                    ..
+                })) => {
                     debug!("Found a h1 in the SUMMARY");
 
-                    let tags = collect_events!(self.stream, end Tag::Heading(HeadingLevel::H1, ..));
+                    let tags = collect_events!(self.stream, end TagEnd::Heading(HeadingLevel::H1));
                     Some(stringify_events(tags))
                 }
 
@@ -336,7 +344,7 @@ impl<'a> SummaryParser<'a> {
     /// Finishes parsing a link once the `Event::Start(Tag::Link(..))` has been opened.
     fn parse_link(&mut self, href: String) -> Link {
         let href = href.replace("%20", " ");
-        let link_content = collect_events!(self.stream, end Tag::Link(..));
+        let link_content = collect_events!(self.stream, end TagEnd::Link);
         let name = stringify_events(link_content);
 
         let path = if href.is_empty() {
@@ -377,7 +385,12 @@ impl<'a> SummaryParser<'a> {
                 }
                 // The expectation is that pulldown cmark will terminate a paragraph before a new
                 // heading, so we can always count on this to return without skipping headings.
-                Some(ev @ Event::Start(Tag::Heading(HeadingLevel::H1, ..))) => {
+                Some(
+                    ev @ Event::Start(Tag::Heading {
+                        level: HeadingLevel::H1,
+                        ..
+                    }),
+                ) => {
                     // we're starting a new part
                     self.back(ev);
                     break;
@@ -398,7 +411,7 @@ impl<'a> SummaryParser<'a> {
 
                     // Skip over the contents of this tag
                     while let Some(event) = self.next_event() {
-                        if event == Event::End(other_tag.clone()) {
+                        if event == Event::End(other_tag.clone().into()) {
                             break;
                         }
                     }
@@ -469,7 +482,7 @@ impl<'a> SummaryParser<'a> {
 
                     last_item.nested_items = sub_items;
                 }
-                Some(Event::End(Tag::List(..))) => break,
+                Some(Event::End(TagEnd::List(..))) => break,
                 Some(_) => {}
                 None => break,
             }
@@ -486,8 +499,8 @@ impl<'a> SummaryParser<'a> {
         loop {
             match self.next_event() {
                 Some(Event::Start(Tag::Paragraph)) => continue,
-                Some(Event::Start(Tag::Link(_type, href, _title))) => {
-                    let mut link = self.parse_link(href.to_string());
+                Some(Event::Start(Tag::Link { dest_url, .. })) => {
+                    let mut link = self.parse_link(dest_url.to_string());
 
                     let mut number = parent.clone();
                     number.0.push(num_existing_items as u32 + 1);
@@ -529,14 +542,18 @@ impl<'a> SummaryParser<'a> {
     fn parse_title(&mut self) -> Option<String> {
         loop {
             match self.next_event() {
-                Some(Event::Start(Tag::Heading(HeadingLevel::H1, ..))) => {
+                Some(Event::Start(Tag::Heading {
+                    level: HeadingLevel::H1,
+                    ..
+                })) => {
                     debug!("Found a h1 in the SUMMARY");
 
-                    let tags = collect_events!(self.stream, end Tag::Heading(HeadingLevel::H1, ..));
+                    let tags = collect_events!(self.stream, end TagEnd::Heading(HeadingLevel::H1));
                     return Some(stringify_events(tags));
                 }
                 // Skip a HTML element such as a comment line.
-                Some(Event::Html(_)) => {}
+                Some(Event::Html(_) | Event::InlineHtml(_))
+                | Some(Event::Start(Tag::HtmlBlock) | Event::End(TagEnd::HtmlBlock)) => {}
                 // Otherwise, no title.
                 Some(ev) => {
                     self.back(ev);
@@ -744,7 +761,7 @@ mod tests {
         let _ = parser.stream.next(); // Discard opening paragraph
 
         let href = match parser.stream.next() {
-            Some((Event::Start(Tag::Link(_type, href, _title)), _range)) => href.to_string(),
+            Some((Event::Start(Tag::Link { dest_url, .. }), _range)) => dest_url.to_string(),
             other => panic!("Unreachable, {:?}", other),
         };
 

src/cmd/watch.rs

@@ -4,6 +4,7 @@ use ignore::gitignore::Gitignore;
 use mdbook::errors::Result;
 use mdbook::utils;
 use mdbook::MDBook;
+use pathdiff::diff_paths;
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::channel;
 use std::thread::sleep;
@@ -86,12 +87,21 @@ fn find_gitignore(book_root: &Path) -> Option<PathBuf> {
         .find(|p| p.exists())
 }
 
+// Note: The usage of `canonicalize` may encounter occasional failures on the Windows platform, presenting a potential risk.
+// For more details, refer to [Pull Request #2229](https://github.com/rust-lang/mdBook/pull/2229#discussion_r1408665981).
 fn filter_ignored_files(ignore: Gitignore, paths: &[PathBuf]) -> Vec<PathBuf> {
+    let ignore_root = ignore
+        .path()
+        .canonicalize()
+        .expect("ignore root canonicalize error");
+
     paths
         .iter()
         .filter(|path| {
+            let relative_path =
+                diff_paths(&path, &ignore_root).expect("One of the paths should be an absolute");
             !ignore
-                .matched_path_or_any_parents(path, path.is_dir())
+                .matched_path_or_any_parents(&relative_path, relative_path.is_dir())
                 .is_ignore()
         })
         .map(|path| path.to_path_buf())
@@ -108,8 +118,7 @@ where
     // Create a channel to receive the events.
     let (tx, rx) = channel();
 
-    let mut debouncer = match notify_debouncer_mini::new_debouncer(Duration::from_secs(1), None, tx)
-    {
+    let mut debouncer = match notify_debouncer_mini::new_debouncer(Duration::from_secs(1), tx) {
         Ok(d) => d,
         Err(e) => {
             error!("Error while trying to watch the files:\n\n\t{:?}", e);
@@ -130,11 +139,16 @@ where
     let _ = watcher.watch(&book.root.join("book.toml"), NonRecursive);
 
     for dir in &book.config.build.extra_watch_dirs {
-        let path = dir.canonicalize().unwrap();
-        if let Err(e) = watcher.watch(&path, Recursive) {
+        let path = book.root.join(dir);
+        let canonical_path = path.canonicalize().unwrap_or_else(|e| {
+            error!("Error while watching extra directory {path:?}:\n    {e}");
+            std::process::exit(1);
+        });
+
+        if let Err(e) = watcher.watch(&canonical_path, Recursive) {
             error!(
                 "Error while watching extra directory {:?}:\n    {:?}",
-                path, e
+                canonical_path, e
             );
             std::process::exit(1);
         }
@@ -152,10 +166,8 @@ where
         let paths: Vec<_> = all_events
             .filter_map(|event| match event {
                 Ok(events) => Some(events),
-                Err(errors) => {
-                    for error in errors {
-                        log::warn!("error while watching for changes: {error}");
-                    }
+                Err(error) => {
+                    log::warn!("error while watching for changes: {error}");
                     None
                 }
             })
@@ -174,3 +186,44 @@ where
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ignore::gitignore::GitignoreBuilder;
+    use std::env;
+
+    #[test]
+    fn test_filter_ignored_files() {
+        let current_dir = env::current_dir().unwrap();
+
+        let ignore = GitignoreBuilder::new(&current_dir)
+            .add_line(None, "*.html")
+            .unwrap()
+            .build()
+            .unwrap();
+        let should_remain = current_dir.join("record.text");
+        let should_filter = current_dir.join("index.html");
+
+        let remain = filter_ignored_files(ignore, &[should_remain.clone(), should_filter]);
+        assert_eq!(remain, vec![should_remain])
+    }
+
+    #[test]
+    fn filter_ignored_files_should_handle_parent_dir() {
+        let current_dir = env::current_dir().unwrap();
+
+        let ignore = GitignoreBuilder::new(&current_dir)
+            .add_line(None, "*.html")
+            .unwrap()
+            .build()
+            .unwrap();
+
+        let parent_dir = current_dir.join("..");
+        let should_remain = parent_dir.join("record.text");
+        let should_filter = parent_dir.join("index.html");
+
+        let remain = filter_ignored_files(ignore, &[should_remain.clone(), should_filter]);
+        assert_eq!(remain, vec![should_remain])
+    }
+}

src/config.rs

@@ -411,6 +411,9 @@ pub struct BookConfig {
     pub multilingual: bool,
     /// The main language of the book.
     pub language: Option<String>,
+    /// The direction of text in the book: Left-to-right (LTR) or Right-to-left (RTL).
+    /// When not specified, the text direction is derived from [`BookConfig::language`].
+    pub text_direction: Option<TextDirection>,
 }
 
 impl Default for BookConfig {
@@ -422,6 +425,43 @@ impl Default for BookConfig {
             src: PathBuf::from("src"),
             multilingual: false,
             language: Some(String::from("en")),
+            text_direction: None,
+        }
+    }
+}
+
+impl BookConfig {
+    /// Gets the realized text direction, either from [`BookConfig::text_direction`]
+    /// or derived from [`BookConfig::language`], to be used by templating engines.
+    pub fn realized_text_direction(&self) -> TextDirection {
+        if let Some(direction) = self.text_direction {
+            direction
+        } else {
+            TextDirection::from_lang_code(self.language.as_deref().unwrap_or_default())
+        }
+    }
+}
+
+/// Text direction to use for HTML output
+#[derive(Debug, Copy, Clone, PartialEq, Serialize, Deserialize)]
+pub enum TextDirection {
+    /// Left to right.
+    #[serde(rename = "ltr")]
+    LeftToRight,
+    /// Right to left
+    #[serde(rename = "rtl")]
+    RightToLeft,
+}
+
+impl TextDirection {
+    /// Gets the text direction from language code
+    pub fn from_lang_code(code: &str) -> Self {
+        match code {
+            // list sourced from here: https://github.com/abarrak/rtl/blob/master/lib/rtl/core.rb#L16
+            "ar" | "ara" | "arc" | "ae" | "ave" | "egy" | "he" | "heb" | "nqo" | "pal" | "phn"
+            | "sam" | "syc" | "syr" | "fa" | "per" | "fas" | "ku" | "kur" | "ur" | "urd"
+            | "pus" | "ps" | "yi" | "yid" => TextDirection::RightToLeft,
+            _ => TextDirection::LeftToRight,
         }
     }
 }
@@ -788,6 +828,7 @@ mod tests {
             multilingual: true,
             src: PathBuf::from("source"),
             language: Some(String::from("ja")),
+            text_direction: None,
         };
         let build_should_be = BuildConfig {
             build_dir: PathBuf::from("outputs"),
@@ -1140,6 +1181,73 @@ mod tests {
         assert_eq!(&get_404_output_file(&html_config.input_404), "missing.html");
     }
 
+    #[test]
+    fn text_direction_ltr() {
+        let src = r#"
+        [book]
+        text-direction = "ltr"
+        "#;
+
+        let got = Config::from_str(src).unwrap();
+        assert_eq!(got.book.text_direction, Some(TextDirection::LeftToRight));
+    }
+
+    #[test]
+    fn text_direction_rtl() {
+        let src = r#"
+        [book]
+        text-direction = "rtl"
+        "#;
+
+        let got = Config::from_str(src).unwrap();
+        assert_eq!(got.book.text_direction, Some(TextDirection::RightToLeft));
+    }
+
+    #[test]
+    fn text_direction_none() {
+        let src = r#"
+        [book]
+        "#;
+
+        let got = Config::from_str(src).unwrap();
+        assert_eq!(got.book.text_direction, None);
+    }
+
+    #[test]
+    fn test_text_direction() {
+        let mut cfg = BookConfig::default();
+
+        // test deriving the text direction from language codes
+        cfg.language = Some("ar".into());
+        assert_eq!(cfg.realized_text_direction(), TextDirection::RightToLeft);
+
+        cfg.language = Some("he".into());
+        assert_eq!(cfg.realized_text_direction(), TextDirection::RightToLeft);
+
+        cfg.language = Some("en".into());
+        assert_eq!(cfg.realized_text_direction(), TextDirection::LeftToRight);
+
+        cfg.language = Some("ja".into());
+        assert_eq!(cfg.realized_text_direction(), TextDirection::LeftToRight);
+
+        // test forced direction
+        cfg.language = Some("ar".into());
+        cfg.text_direction = Some(TextDirection::LeftToRight);
+        assert_eq!(cfg.realized_text_direction(), TextDirection::LeftToRight);
+
+        cfg.language = Some("ar".into());
+        cfg.text_direction = Some(TextDirection::RightToLeft);
+        assert_eq!(cfg.realized_text_direction(), TextDirection::RightToLeft);
+
+        cfg.language = Some("en".into());
+        cfg.text_direction = Some(TextDirection::LeftToRight);
+        assert_eq!(cfg.realized_text_direction(), TextDirection::LeftToRight);
+
+        cfg.language = Some("en".into());
+        cfg.text_direction = Some(TextDirection::RightToLeft);
+        assert_eq!(cfg.realized_text_direction(), TextDirection::RightToLeft);
+    }
+
     #[test]
     #[should_panic(expected = "Invalid configuration file")]
     fn invalid_language_type_error() {

src/renderer/html_handlebars/hbs_renderer.rs

@@ -54,8 +54,7 @@ impl HtmlHandlebars {
                 .insert("git_repository_edit_url".to_owned(), json!(edit_url));
         }
 
-        let content = ch.content.clone();
-        let content = utils::render_markdown(&content, ctx.html_config.curly_quotes);
+        let content = utils::render_markdown(&ch.content, ctx.html_config.curly_quotes);
 
         let fixed_content =
             utils::render_markdown_with_path(&ch.content, ctx.html_config.curly_quotes, Some(path));
@@ -478,25 +477,6 @@ impl HtmlHandlebars {
     }
 }
 
-// TODO(mattico): Remove some time after the 0.1.8 release
-fn maybe_wrong_theme_dir(dir: &Path) -> Result<bool> {
-    fn entry_is_maybe_book_file(entry: fs::DirEntry) -> Result<bool> {
-        Ok(entry.file_type()?.is_file()
-            && entry.path().extension().map_or(false, |ext| ext == "md"))
-    }
-
-    if dir.is_dir() {
-        for entry in fs::read_dir(dir)? {
-            if entry_is_maybe_book_file(entry?).unwrap_or(false) {
-                return Ok(false);
-            }
-        }
-        Ok(true)
-    } else {
-        Ok(false)
-    }
-}
-
 impl Renderer for HtmlHandlebars {
     fn name(&self) -> &str {
         "html"
@@ -529,16 +509,6 @@ impl Renderer for HtmlHandlebars {
             None => ctx.root.join("theme"),
         };
 
-        if html_config.theme.is_none()
-            && maybe_wrong_theme_dir(&src_dir.join("theme")).unwrap_or(false)
-        {
-            warn!(
-                "Previous versions of mdBook erroneously accepted `./src/theme` as an automatic \
-                 theme directory"
-            );
-            warn!("Please move your theme files to `./theme` for them to continue being used");
-        }
-
         let theme = theme::Theme::new(theme_dir);
 
         debug!("Register the index handlebars template");
@@ -648,6 +618,10 @@ fn make_data(
         "language".to_owned(),
         json!(config.book.language.clone().unwrap_or_default()),
     );
+    data.insert(
+        "text_direction".to_owned(),
+        json!(config.book.realized_text_direction()),
+    );
     data.insert(
         "book_title".to_owned(),
         json!(config.book.title.clone().unwrap_or_default()),
@@ -961,8 +935,9 @@ fn add_playground_pre(
 /// 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();
+    static LANGUAGE_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\blanguage-(\w+)\b").unwrap());
+    static HIDELINES_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\bhidelines=(\S+)").unwrap());
+
     CODE_BLOCK_RE
         .replace_all(html, |caps: &Captures<'_>| {
             let text = &caps[1];
@@ -977,12 +952,12 @@ fn hide_lines(html: &str, code_config: &Code) -> String {
                 )
             } else {
                 // First try to get the prefix from the code block
-                let hidelines_capture = hidelines_regex.captures(classes);
+                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| {
+                        LANGUAGE_REGEX.captures(classes).and_then(|capture| {
                             code_config.hidelines.get(&capture[1]).map(|p| p.as_str())
                         })
                     }
@@ -1088,6 +1063,8 @@ struct RenderItemContext<'a> {
 
 #[cfg(test)]
 mod tests {
+    use crate::config::TextDirection;
+
     use super::*;
     use pretty_assertions::assert_eq;
 
@@ -1299,4 +1276,10 @@ mod tests {
             assert_eq!(&*got, *should_be);
         }
     }
+
+    #[test]
+    fn test_json_direction() {
+        assert_eq!(json!(TextDirection::RightToLeft), json!("rtl"));
+        assert_eq!(json!(TextDirection::LeftToRight), json!("ltr"));
+    }
 }

src/renderer/html_handlebars/helpers/navigation.rs

@@ -1,7 +1,9 @@
 use std::collections::BTreeMap;
 use std::path::Path;
 
-use handlebars::{Context, Handlebars, Helper, Output, RenderContext, RenderError, Renderable};
+use handlebars::{
+    Context, Handlebars, Helper, Output, RenderContext, RenderError, RenderErrorReason, Renderable,
+};
 
 use crate::utils;
 use log::{debug, trace};
@@ -26,9 +28,9 @@ impl Target {
     ) -> Result<Option<StringMap>, RenderError> {
         match *self {
             Target::Next => {
-                let previous_path = previous_item
-                    .get("path")
-                    .ok_or_else(|| RenderError::new("No path found for chapter in JSON data"))?;
+                let previous_path = previous_item.get("path").ok_or_else(|| {
+                    RenderErrorReason::Other("No path found for chapter in JSON data".to_owned())
+                })?;
 
                 if previous_path == base_path {
                     return Ok(Some(current_item.clone()));
@@ -54,15 +56,18 @@ fn find_chapter(
     debug!("Get data from context");
 
     let chapters = rc.evaluate(ctx, "@root/chapters").and_then(|c| {
-        serde_json::value::from_value::<Vec<StringMap>>(c.as_json().clone())
-            .map_err(|_| RenderError::new("Could not decode the JSON data"))
+        serde_json::value::from_value::<Vec<StringMap>>(c.as_json().clone()).map_err(|_| {
+            RenderErrorReason::Other("Could not decode the JSON data".to_owned()).into()
+        })
     })?;
 
     let base_path = rc
         .evaluate(ctx, "@root/path")?
         .as_json()
         .as_str()
-        .ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
+        .ok_or_else(|| {
+            RenderErrorReason::Other("Type error for `path`, string expected".to_owned())
+        })?
         .replace('\"', "");
 
     if !rc.evaluate(ctx, "@root/is_index")?.is_missing() {
@@ -98,7 +103,7 @@ fn find_chapter(
                     }
                 }
 
-                previous = Some(item.clone());
+                previous = Some(item);
             }
             _ => continue,
         }
@@ -108,7 +113,7 @@ fn find_chapter(
 }
 
 fn render(
-    _h: &Helper<'_, '_>,
+    _h: &Helper<'_>,
     r: &Handlebars<'_>,
     ctx: &Context,
     rc: &mut RenderContext<'_, '_>,
@@ -122,7 +127,9 @@ fn render(
         .evaluate(ctx, "@root/path")?
         .as_json()
         .as_str()
-        .ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
+        .ok_or_else(|| {
+            RenderErrorReason::Other("Type error for `path`, string expected".to_owned())
+        })?
         .replace('\"', "");
 
     context.insert(
@@ -132,17 +139,23 @@ fn render(
 
     chapter
         .get("name")
-        .ok_or_else(|| RenderError::new("No title found for chapter in JSON data"))
+        .ok_or_else(|| {
+            RenderErrorReason::Other("No title found for chapter in JSON data".to_owned())
+        })
         .map(|name| context.insert("title".to_owned(), json!(name)))?;
 
     chapter
         .get("path")
-        .ok_or_else(|| RenderError::new("No path found for chapter in JSON data"))
+        .ok_or_else(|| {
+            RenderErrorReason::Other("No path found for chapter in JSON data".to_owned())
+        })
         .and_then(|p| {
             Path::new(p)
                 .with_extension("html")
                 .to_str()
-                .ok_or_else(|| RenderError::new("Link could not be converted to str"))
+                .ok_or_else(|| {
+                    RenderErrorReason::Other("Link could not be converted to str".to_owned())
+                })
                 .map(|p| context.insert("link".to_owned(), json!(p.replace('\\', "/"))))
         })?;
 
@@ -150,14 +163,14 @@ fn render(
 
     let t = _h
         .template()
-        .ok_or_else(|| RenderError::new("Error with the handlebars template"))?;
+        .ok_or_else(|| RenderErrorReason::Other("Error with the handlebars template".to_owned()))?;
     let local_ctx = Context::wraps(&context)?;
     let mut local_rc = rc.clone();
     t.render(r, &local_ctx, &mut local_rc, out)
 }
 
 pub fn previous(
-    _h: &Helper<'_, '_>,
+    _h: &Helper<'_>,
     r: &Handlebars<'_>,
     ctx: &Context,
     rc: &mut RenderContext<'_, '_>,
@@ -173,7 +186,7 @@ pub fn previous(
 }
 
 pub fn next(
-    _h: &Helper<'_, '_>,
+    _h: &Helper<'_>,
     r: &Handlebars<'_>,
     ctx: &Context,
     rc: &mut RenderContext<'_, '_>,

src/renderer/html_handlebars/helpers/theme.rs

@@ -1,8 +1,10 @@
-use handlebars::{Context, Handlebars, Helper, Output, RenderContext, RenderError};
+use handlebars::{
+    Context, Handlebars, Helper, Output, RenderContext, RenderError, RenderErrorReason,
+};
 use log::trace;
 
 pub fn theme_option(
-    h: &Helper<'_, '_>,
+    h: &Helper<'_>,
     _r: &Handlebars<'_>,
     ctx: &Context,
     rc: &mut RenderContext<'_, '_>,
@@ -11,14 +13,21 @@ pub fn theme_option(
     trace!("theme_option (handlebars helper)");
 
     let param = h.param(0).and_then(|v| v.value().as_str()).ok_or_else(|| {
-        RenderError::new("Param 0 with String type is required for theme_option helper.")
+        RenderErrorReason::ParamTypeMismatchForName(
+            "theme_option",
+            "0".to_owned(),
+            "string".to_owned(),
+        )
     })?;
 
     let default_theme = rc.evaluate(ctx, "@root/default_theme")?;
-    let default_theme_name = default_theme
-        .as_json()
-        .as_str()
-        .ok_or_else(|| RenderError::new("Type error for `default_theme`, string expected"))?;
+    let default_theme_name = default_theme.as_json().as_str().ok_or_else(|| {
+        RenderErrorReason::ParamTypeMismatchForName(
+            "theme_option",
+            "default_theme".to_owned(),
+            "string".to_owned(),
+        )
+    })?;
 
     out.write(param)?;
     if param.to_lowercase() == default_theme_name.to_lowercase() {

src/renderer/html_handlebars/helpers/toc.rs

@@ -4,7 +4,9 @@ use std::{cmp::Ordering, collections::BTreeMap};
 use crate::utils;
 use crate::utils::bracket_escape;
 
-use handlebars::{Context, Handlebars, Helper, HelperDef, Output, RenderContext, RenderError};
+use handlebars::{
+    Context, Handlebars, Helper, HelperDef, Output, RenderContext, RenderError, RenderErrorReason,
+};
 
 // Handlebars helper to construct TOC
 #[derive(Clone, Copy)]
@@ -15,7 +17,7 @@ pub struct RenderToc {
 impl HelperDef for RenderToc {
     fn call<'reg: 'rc, 'rc>(
         &self,
-        _h: &Helper<'reg, 'rc>,
+        _h: &Helper<'rc>,
         _r: &'reg Handlebars<'_>,
         ctx: &'rc Context,
         rc: &mut RenderContext<'reg, 'rc>,
@@ -26,13 +28,17 @@ impl HelperDef for RenderToc {
         // param is the key of value you want to display
         let chapters = rc.evaluate(ctx, "@root/chapters").and_then(|c| {
             serde_json::value::from_value::<Vec<BTreeMap<String, String>>>(c.as_json().clone())
-                .map_err(|_| RenderError::new("Could not decode the JSON data"))
+                .map_err(|_| {
+                    RenderErrorReason::Other("Could not decode the JSON data".to_owned()).into()
+                })
         })?;
         let current_path = rc
             .evaluate(ctx, "@root/path")?
             .as_json()
             .as_str()
-            .ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
+            .ok_or_else(|| {
+                RenderErrorReason::Other("Type error for `path`, string expected".to_owned())
+            })?
             .replace('\"', "");
 
         let current_section = rc
@@ -46,13 +52,17 @@ impl HelperDef for RenderToc {
             .evaluate(ctx, "@root/fold_enable")?
             .as_json()
             .as_bool()
-            .ok_or_else(|| RenderError::new("Type error for `fold_enable`, bool expected"))?;
+            .ok_or_else(|| {
+                RenderErrorReason::Other("Type error for `fold_enable`, bool expected".to_owned())
+            })?;
 
         let fold_level = rc
             .evaluate(ctx, "@root/fold_level")?
             .as_json()
             .as_u64()
-            .ok_or_else(|| RenderError::new("Type error for `fold_level`, u64 expected"))?;
+            .ok_or_else(|| {
+                RenderErrorReason::Other("Type error for `fold_level`, u64 expected".to_owned())
+            })?;
 
         out.write("<ol class=\"chapter\">")?;
 

src/renderer/html_handlebars/search.rs

@@ -66,10 +66,23 @@ fn add_doc(
     index: &mut Index,
     doc_urls: &mut Vec<String>,
     anchor_base: &str,
-    section_id: &Option<String>,
+    heading: &str,
+    id_counter: &mut HashMap<String, usize>,
+    section_id: &Option<CowStr<'_>>,
     items: &[&str],
 ) {
-    let url = if let Some(ref id) = *section_id {
+    // Either use the explicit section id the user specified, or generate one
+    // from the heading content.
+    let section_id = section_id.as_ref().map(|id| id.to_string()).or_else(|| {
+        if heading.is_empty() {
+            // In the case where a chapter has no heading, don't set a section id.
+            None
+        } else {
+            Some(utils::unique_id_from_content(heading, id_counter))
+        }
+    });
+
+    let url = if let Some(id) = section_id {
         Cow::Owned(format!("{}#{}", anchor_base, id))
     } else {
         Cow::Borrowed(anchor_base)
@@ -119,7 +132,7 @@ fn render_item(
     let mut id_counter = HashMap::new();
     while let Some(event) = p.next() {
         match event {
-            Event::Start(Tag::Heading(i, ..)) if i as u32 <= max_section_depth => {
+            Event::Start(Tag::Heading { level, id, .. }) if level as u32 <= max_section_depth => {
                 if !heading.is_empty() {
                     // Section finished, the next heading is following now
                     // Write the data to the index, and clear it for the next section
@@ -127,22 +140,21 @@ fn render_item(
                         index,
                         doc_urls,
                         &anchor_base,
+                        &heading,
+                        &mut id_counter,
                         &section_id,
                         &[&heading, &body, &breadcrumbs.join(" » ")],
                     );
-                    section_id = None;
                     heading.clear();
                     body.clear();
                     breadcrumbs.pop();
                 }
 
+                section_id = id;
                 in_heading = true;
             }
-            Event::End(Tag::Heading(i, id, _classes)) if i as u32 <= max_section_depth => {
+            Event::End(TagEnd::Heading(level)) if level as u32 <= max_section_depth => {
                 in_heading = false;
-                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)) => {
@@ -159,9 +171,19 @@ fn render_item(
                     html_block.push_str(html);
                     p.next();
                 }
-
                 body.push_str(&clean_html(&html_block));
             }
+            Event::InlineHtml(html) => {
+                // This is not capable of cleaning inline tags like
+                // `foo <script>…</script>`. The `<script>` tags show up as
+                // individual InlineHtml events, and the content inside is
+                // just a regular Text event. There isn't a very good way to
+                // know how to collect all the content in-between. I'm not
+                // sure if this is easily fixable. It should be extremely
+                // rare, since script and style tags should almost always be
+                // blocks, and worse case you have some noise in the index.
+                body.push_str(&clean_html(&html));
+            }
             Event::Start(_) | Event::End(_) | Event::Rule | Event::SoftBreak | Event::HardBreak => {
                 // Insert spaces where HTML output would usually separate text
                 // to ensure words don't get merged together
@@ -188,18 +210,24 @@ fn render_item(
     }
 
     if !body.is_empty() || !heading.is_empty() {
-        if heading.is_empty() {
+        let title = if heading.is_empty() {
             if let Some(chapter) = breadcrumbs.first() {
-                heading = chapter.clone();
+                chapter
+            } else {
+                ""
             }
-        }
+        } else {
+            &heading
+        };
         // Make sure the last section is added to the index
         add_doc(
             index,
             doc_urls,
             &anchor_base,
+            &heading,
+            &mut id_counter,
             &section_id,
-            &[&heading, &body, &breadcrumbs.join(" » ")],
+            &[title, &body, &breadcrumbs.join(" » ")],
         );
     }
 

src/theme/book.js

@@ -441,7 +441,7 @@ function playground_text(playground, hidden = true) {
 })();
 
 (function sidebar() {
-    var html = document.querySelector("html");
+    var body = document.querySelector("body");
     var sidebar = document.getElementById("sidebar");
     var sidebarLinks = document.querySelectorAll('#sidebar a');
     var sidebarToggleButton = document.getElementById("sidebar-toggle");
@@ -449,8 +449,8 @@ function playground_text(playground, hidden = true) {
     var firstContact = null;
 
     function showSidebar() {
-        html.classList.remove('sidebar-hidden')
-        html.classList.add('sidebar-visible');
+        body.classList.remove('sidebar-hidden')
+        body.classList.add('sidebar-visible');
         Array.from(sidebarLinks).forEach(function (link) {
             link.setAttribute('tabIndex', 0);
         });
@@ -471,8 +471,8 @@ function playground_text(playground, hidden = true) {
     });
 
     function hideSidebar() {
-        html.classList.remove('sidebar-visible')
-        html.classList.add('sidebar-hidden');
+        body.classList.remove('sidebar-visible')
+        body.classList.add('sidebar-hidden');
         Array.from(sidebarLinks).forEach(function (link) {
             link.setAttribute('tabIndex', -1);
         });
@@ -483,14 +483,14 @@ function playground_text(playground, hidden = true) {
 
     // Toggle sidebar
     sidebarToggleButton.addEventListener('click', function sidebarToggle() {
-        if (html.classList.contains("sidebar-hidden")) {
+        if (body.classList.contains("sidebar-hidden")) {
             var current_width = parseInt(
                 document.documentElement.style.getPropertyValue('--sidebar-width'), 10);
             if (current_width < 150) {
                 document.documentElement.style.setProperty('--sidebar-width', '150px');
             }
             showSidebar();
-        } else if (html.classList.contains("sidebar-visible")) {
+        } else if (body.classList.contains("sidebar-visible")) {
             hideSidebar();
         } else {
             if (getComputedStyle(sidebar)['transform'] === 'none') {
@@ -506,14 +506,14 @@ function playground_text(playground, hidden = true) {
     function initResize(e) {
         window.addEventListener('mousemove', resize, false);
         window.addEventListener('mouseup', stopResize, false);
-        html.classList.add('sidebar-resizing');
+        body.classList.add('sidebar-resizing');
     }
     function resize(e) {
         var pos = (e.clientX - sidebar.offsetLeft);
         if (pos < 20) {
             hideSidebar();
         } else {
-            if (html.classList.contains("sidebar-hidden")) {
+            if (body.classList.contains("sidebar-hidden")) {
                 showSidebar();
             }
             pos = Math.min(pos, window.innerWidth - 100);
@@ -522,7 +522,7 @@ function playground_text(playground, hidden = true) {
     }
     //on mouseup remove windows functions mousemove & mouseup
     function stopResize(e) {
-        html.classList.remove('sidebar-resizing');
+        body.classList.remove('sidebar-resizing');
         window.removeEventListener('mousemove', resize, false);
         window.removeEventListener('mouseup', stopResize, false);
     }
@@ -557,20 +557,35 @@ function playground_text(playground, hidden = true) {
     document.addEventListener('keydown', function (e) {
         if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) { return; }
         if (window.search && window.search.hasFocus()) { return; }
+        var html = document.querySelector('html');
 
+        function next() {
+            var nextButton = document.querySelector('.nav-chapters.next');
+            if (nextButton) {
+                window.location.href = nextButton.href;
+            }
+        }
+        function prev() {
+            var previousButton = document.querySelector('.nav-chapters.previous');
+            if (previousButton) {
+                window.location.href = previousButton.href;
+            }
+        }
         switch (e.key) {
             case 'ArrowRight':
                 e.preventDefault();
-                var nextButton = document.querySelector('.nav-chapters.next');
-                if (nextButton) {
-                    window.location.href = nextButton.href;
+                if (html.dir == 'rtl') {
+                    prev();
+                } else {
+                    next();
                 }
                 break;
             case 'ArrowLeft':
                 e.preventDefault();
-                var previousButton = document.querySelector('.nav-chapters.previous');
-                if (previousButton) {
-                    window.location.href = previousButton.href;
+                if (html.dir == 'rtl') {
+                    next();
+                } else {
+                    prev();
                 }
                 break;
         }

src/theme/css/chrome.css

@@ -37,9 +37,9 @@ a > .hljs {
     display: flex;
     flex-wrap: wrap;
     background-color: var(--bg);
-    border-bottom-color: var(--bg);
-    border-bottom-width: 1px;
-    border-bottom-style: solid;
+    border-block-end-color: var(--bg);
+    border-block-end-width: 1px;
+    border-block-end-style: solid;
 }
 #menu-bar.sticky,
 .js #menu-bar-hover-placeholder:hover + #menu-bar,
@@ -56,7 +56,7 @@ a > .hljs {
     height: var(--menu-bar-height);
 }
 #menu-bar.bordered {
-    border-bottom-color: var(--table-border-color);
+    border-block-end-color: var(--table-border-color);
 }
 #menu-bar i, #menu-bar .icon-button {
     position: relative;
@@ -93,7 +93,7 @@ a > .hljs {
     display: flex;
     margin: 0 5px;
 }
-.no-js .left-buttons {
+.no-js .left-buttons button {
     display: none;
 }
 
@@ -160,7 +160,7 @@ a > .hljs {
 }
 
 .nav-wrapper {
-    margin-top: 50px;
+    margin-block-start: 50px;
     display: none;
 }
 
@@ -173,23 +173,34 @@ a > .hljs {
     background-color: var(--sidebar-bg);
 }
 
-.previous {
-    float: left;
-}
+/* Only Firefox supports flow-relative values */
+.previous { float: left; }
+[dir=rtl] .previous { float: right; }
 
+/* Only Firefox supports flow-relative values */
 .next {
     float: right;
     right: var(--page-padding);
 }
+[dir=rtl] .next {
+    float: left;
+    right: unset;
+    left: var(--page-padding);
+}
+
+/* Use the correct buttons for RTL layouts*/
+[dir=rtl] .previous i.fa-angle-left:before {content:"\f105";}
+[dir=rtl] .next i.fa-angle-right:before { content:"\f104"; }
 
 @media only screen and (max-width: 1080px) {
     .nav-wide-wrapper { display: none; }
     .nav-wrapper { display: block; }
 }
 
+/* sidebar-visible */
 @media only screen and (max-width: 1380px) {
-    .sidebar-visible .nav-wide-wrapper { display: none; }
-    .sidebar-visible .nav-wrapper { display: block; }
+    #sidebar-toggle-anchor:checked ~ .page-wrapper .nav-wide-wrapper { display: none; }
+    #sidebar-toggle-anchor:checked ~ .page-wrapper .nav-wrapper { display: block; }
 }
 
 /* Inline code */
@@ -236,7 +247,7 @@ pre > .buttons :hover {
     background-color: var(--theme-hover);
 }
 pre > .buttons i {
-    margin-left: 8px;
+    margin-inline-start: 8px;
 }
 pre > .buttons button {
     cursor: inherit;
@@ -258,8 +269,14 @@ pre > .buttons button {
         /* On mobile, make it easier to tap buttons. */
         padding: 0.3rem 1rem;
     }
+
+    .sidebar-resize-indicator {
+        /* Hide resize indicator on devices with limited accuracy */
+        display: none;
+    }
 }
 pre > code {
+    display: block;
     padding: 1rem;
 }
 
@@ -273,7 +290,7 @@ pre > code {
 }
 
 pre > .result {
-    margin-top: 10px;
+    margin-block-start: 10px;
 }
 
 /* Search */
@@ -284,8 +301,14 @@ pre > .result {
 
 mark {
     border-radius: 2px;
-    padding: 0 3px 1px 3px;
-    margin: 0 -3px -1px -3px;
+    padding-block-start: 0;
+    padding-block-end: 1px;
+    padding-inline-start: 3px;
+    padding-inline-end: 3px;
+    margin-block-start: 0;
+    margin-block-end: -1px;
+    margin-inline-start: -3px;
+    margin-inline-end: -3px;
     background-color: var(--search-mark-bg);
     transition: background-color 300ms linear;
     cursor: pointer;
@@ -297,14 +320,17 @@ mark.fade-out {
 }
 
 .searchbar-outer {
-    margin-left: auto;
-    margin-right: auto;
+    margin-inline-start: auto;
+    margin-inline-end: auto;
     max-width: var(--content-max-width);
 }
 
 #searchbar {
     width: 100%;
-    margin: 5px auto 0px auto;
+    margin-block-start: 5px;
+    margin-block-end: 0;
+    margin-inline-start: auto;
+    margin-inline-end: auto;
     padding: 10px 16px;
     transition: box-shadow 300ms ease-in-out;
     border: 1px solid var(--searchbar-border-color);
@@ -320,20 +346,23 @@ mark.fade-out {
 .searchresults-header {
     font-weight: bold;
     font-size: 1em;
-    padding: 18px 0 0 5px;
+    padding-block-start: 18px;
+    padding-block-end: 0;
+    padding-inline-start: 5px;
+    padding-inline-end: 0;
     color: var(--searchresults-header-fg);
 }
 
 .searchresults-outer {
-    margin-left: auto;
-    margin-right: auto;
+    margin-inline-start: auto;
+    margin-inline-end: auto;
     max-width: var(--content-max-width);
-    border-bottom: 1px dashed var(--searchresults-border-color);
+    border-block-end: 1px dashed var(--searchresults-border-color);
 }
 
 ul#searchresults {
     list-style: none;
-    padding-left: 20px;
+    padding-inline-start: 20px;
 }
 ul#searchresults li {
     margin: 10px 0px;
@@ -346,7 +375,10 @@ ul#searchresults li.focus {
 ul#searchresults span.teaser {
     display: block;
     clear: both;
-    margin: 5px 0 0 20px;
+    margin-block-start: 5px;
+    margin-block-end: 0;
+    margin-inline-start: 20px;
+    margin-inline-end: 0;
     font-size: 0.8em;
 }
 ul#searchresults span.teaser em {
@@ -369,12 +401,14 @@ ul#searchresults span.teaser em {
     background-color: var(--sidebar-bg);
     color: var(--sidebar-fg);
 }
+[dir=rtl] .sidebar { left: unset; right: 0; }
 .sidebar-resizing {
     -moz-user-select: none;
     -webkit-user-select: none;
     -ms-user-select: none;
     user-select: none;
 }
+.no-js .sidebar,
 .js:not(.sidebar-resizing) .sidebar {
     transition: transform 0.3s; /* Animation: slide away */
 }
@@ -394,16 +428,35 @@ ul#searchresults span.teaser em {
     position: absolute;
     cursor: col-resize;
     width: 0;
-    right: 0;
+    right: calc(var(--sidebar-resize-indicator-width) * -1);
     top: 0;
     bottom: 0;
+    display: flex;
+    align-items: center;
+}
+
+.sidebar-resize-handle .sidebar-resize-indicator {
+    width: 100%;
+    height: 12px;
+    background-color: var(--icons);
+    margin-inline-start: var(--sidebar-resize-indicator-space);
+}
+
+[dir=rtl] .sidebar .sidebar-resize-handle {
+    left: calc(var(--sidebar-resize-indicator-width) * -1);
+    right: unset;
 }
 .js .sidebar .sidebar-resize-handle {
     cursor: col-resize;
-    width: 5px;
+    width: calc(var(--sidebar-resize-indicator-width) - var(--sidebar-resize-indicator-space));
 }
-.sidebar-hidden .sidebar {
-    transform: translateX(calc(0px - var(--sidebar-width)));
+/* sidebar-hidden */
+#sidebar-toggle-anchor:not(:checked) ~ .sidebar {
+    transform: translateX(calc(0px - var(--sidebar-width) - var(--sidebar-resize-indicator-width)));
+    z-index: -1;
+}
+[dir=rtl] #sidebar-toggle-anchor:not(:checked) ~ .sidebar {
+    transform: translateX(calc(var(--sidebar-width) + var(--sidebar-resize-indicator-width)));
 }
 .sidebar::-webkit-scrollbar {
     background: var(--sidebar-bg);
@@ -412,19 +465,26 @@ ul#searchresults span.teaser em {
     background: var(--scrollbar);
 }
 
-.sidebar-visible .page-wrapper {
-    transform: translateX(var(--sidebar-width));
+/* sidebar-visible */
+#sidebar-toggle-anchor:checked ~ .page-wrapper {
+    transform: translateX(calc(var(--sidebar-width) + var(--sidebar-resize-indicator-width)));
+}
+[dir=rtl] #sidebar-toggle-anchor:checked ~ .page-wrapper {
+    transform: translateX(calc(0px - var(--sidebar-width) - var(--sidebar-resize-indicator-width)));
 }
 @media only screen and (min-width: 620px) {
-    .sidebar-visible .page-wrapper {
+    #sidebar-toggle-anchor:checked ~ .page-wrapper {
+        transform: none;
+        margin-inline-start: calc(var(--sidebar-width) + var(--sidebar-resize-indicator-width));
+    }
+    [dir=rtl] #sidebar-toggle-anchor:checked ~ .page-wrapper {
         transform: none;
-        margin-left: var(--sidebar-width);
     }
 }
 
 .chapter {
     list-style: none outside none;
-    padding-left: 0;
+    padding-inline-start: 0;
     line-height: 2.2em;
 }
 
@@ -454,7 +514,7 @@ ul#searchresults span.teaser em {
 .chapter li > a.toggle {
     cursor: pointer;
     display: block;
-    margin-left: auto;
+    margin-inline-start: auto;
     padding: 0 10px;
     user-select: none;
     opacity: 0.68;
@@ -471,7 +531,7 @@ ul#searchresults span.teaser em {
 
 .chapter li.chapter-item {
     line-height: 1.5em;
-    margin-top: 0.6em;
+    margin-block-start: 0.6em;
 }
 
 .chapter li.expanded > a.toggle div {
@@ -494,7 +554,7 @@ ul#searchresults span.teaser em {
 
 .section {
     list-style: none outside none;
-    padding-left: 20px;
+    padding-inline-start: 20px;
     line-height: 1.9em;
 }
 
@@ -517,6 +577,7 @@ ul#searchresults span.teaser em {
     /* Don't let the children's background extend past the rounded corners. */
     overflow: hidden;
 }
+[dir=rtl] .theme-popup { left: unset;  right: 10px; }
 .theme-popup .default {
     color: var(--icons);
 }
@@ -527,7 +588,7 @@ ul#searchresults span.teaser em {
     padding: 2px 20px;
     line-height: 25px;
     white-space: nowrap;
-    text-align: left;
+    text-align: start;
     cursor: pointer;
     color: inherit;
     background: inherit;
@@ -540,6 +601,6 @@ ul#searchresults span.teaser em {
 .theme-selected::before {
     display: inline-block;
     content: "✓";
-    margin-left: -14px;
+    margin-inline-start: -14px;
     width: 14px;
 }

src/theme/css/general.css

@@ -5,6 +5,7 @@
 :root {
     /* Browser default font-size is 16px, this way 1 rem = 10px */
     font-size: 62.5%;
+    color-scheme: var(--color-scheme);
 }
 
 html {
@@ -24,6 +25,7 @@ body {
 code {
     font-family: var(--mono-font) !important;
     font-size: var(--code-font-size);
+    direction: ltr !important;
 }
 
 /* make long words/inline code not x overflow */
@@ -47,13 +49,13 @@ h1 code, h2 code, h3 code, h4 code, h5 code, h6 code {
 .hide-boring .boring { display: none; }
 .hidden { display: none !important; }
 
-h2, h3 { margin-top: 2.5em; }
-h4, h5 { margin-top: 2em; }
+h2, h3 { margin-block-start: 2.5em; }
+h4, h5 { margin-block-start: 2em; }
 
 .header + .header h3,
 .header + .header h4,
 .header + .header h5 {
-    margin-top: 1em;
+    margin-block-start: 1em;
 }
 
 h1:target::before,
@@ -64,7 +66,7 @@ h5:target::before,
 h6:target::before {
     display: inline-block;
     content: "»";
-    margin-left: -30px;
+    margin-inline-start: -30px;
     width: 30px;
 }
 
@@ -73,28 +75,34 @@ h6:target::before {
    https://bugs.webkit.org/show_bug.cgi?id=218076
 */
 :target {
+    /* Safari does not support logical properties */
     scroll-margin-top: calc(var(--menu-bar-height) + 0.5em);
 }
 
 .page {
     outline: 0;
     padding: 0 var(--page-padding);
-    margin-top: calc(0px - var(--menu-bar-height)); /* Compensate for the #menu-bar-hover-placeholder */
+    margin-block-start: calc(0px - var(--menu-bar-height)); /* Compensate for the #menu-bar-hover-placeholder */
 }
 .page-wrapper {
     box-sizing: border-box;
+    background-color: var(--bg);
 }
+.no-js .page-wrapper,
 .js:not(.sidebar-resizing) .page-wrapper {
     transition: margin-left 0.3s ease, transform 0.3s ease; /* Animation: slide away */
 }
+[dir=rtl] .js:not(.sidebar-resizing) .page-wrapper {
+    transition: margin-right 0.3s ease, transform 0.3s ease; /* Animation: slide away */
+}
 
 .content {
     overflow-y: auto;
     padding: 0 5px 50px 5px;
 }
 .content main {
-    margin-left: auto;
-    margin-right: auto;
+    margin-inline-start: auto;
+    margin-inline-end: auto;
     max-width: var(--content-max-width);
 }
 .content p { line-height: 1.45em; }
@@ -144,8 +152,31 @@ blockquote {
     padding: 0 20px;
     color: var(--fg);
     background-color: var(--quote-bg);
-    border-top: .1em solid var(--quote-border);
-    border-bottom: .1em solid var(--quote-border);
+    border-block-start: .1em solid var(--quote-border);
+    border-block-end: .1em solid var(--quote-border);
+}
+
+.warning {
+    margin: 20px;
+    padding: 0 20px;
+    border-inline-start: 2px solid var(--warning-border);
+}
+
+.warning:before {
+    position: absolute;
+    width: 3rem;
+    height: 3rem;
+    margin-inline-start: calc(-1.5rem - 21px);
+    content: "ⓘ";
+    text-align: center;
+    background-color: var(--bg);
+    color: var(--warning-border);
+    font-weight: bold;
+    font-size: 2rem;
+}
+
+blockquote .warning:before {
+    background-color: var(--quote-bg);
 }
 
 kbd {
@@ -163,7 +194,7 @@ kbd {
 
 :not(.footnote-definition) + .footnote-definition,
 .footnote-definition + :not(.footnote-definition) {
-    margin-top: 2em;
+    margin-block-start: 2em;
 }
 .footnote-definition {
     font-size: 0.9em;

src/theme/css/print.css

@@ -7,8 +7,8 @@
 }
 
 #page-wrapper.page-wrapper {
-    transform: none;
-    margin-left: 0px;
+    transform: none !important;
+    margin-inline-start: 0px;
     overflow-y: initial;
 }
 
@@ -23,11 +23,7 @@
 }
 
 code {
-    background-color: #666666;
-    border-radius: 5px;
-
-    /* Force background to be printed in Chrome */
-    -webkit-print-color-adjust: exact;
+    direction: ltr !important;
 }
 
 pre > .buttons {

src/theme/css/variables.css

@@ -3,6 +3,8 @@
 
 :root {
     --sidebar-width: 300px;
+    --sidebar-resize-indicator-width: 8px;
+    --sidebar-resize-indicator-space: 2px;
     --page-padding: 15px;
     --content-max-width: 750px;
     --menu-bar-height: 50px;
@@ -38,6 +40,8 @@
     --quote-bg: hsl(226, 15%, 17%);
     --quote-border: hsl(226, 15%, 22%);
 
+    --warning-border: #ff8e00;
+
     --table-border-color: hsl(210, 25%, 13%);
     --table-header-bg: hsl(210, 25%, 28%);
     --table-alternate-bg: hsl(210, 25%, 11%);
@@ -50,6 +54,8 @@
     --searchresults-border-color: #888;
     --searchresults-li-bg: #252932;
     --search-mark-bg: #e3b171;
+
+    --color-scheme: dark;
 }
 
 .coal {
@@ -78,6 +84,8 @@
     --quote-bg: hsl(234, 21%, 18%);
     --quote-border: hsl(234, 21%, 23%);
 
+    --warning-border: #ff8e00;
+
     --table-border-color: hsl(200, 7%, 13%);
     --table-header-bg: hsl(200, 7%, 28%);
     --table-alternate-bg: hsl(200, 7%, 11%);
@@ -90,6 +98,8 @@
     --searchresults-border-color: #98a3ad;
     --searchresults-li-bg: #2b2b2f;
     --search-mark-bg: #355c7d;
+
+    --color-scheme: dark;
 }
 
 .light {
@@ -118,6 +128,8 @@
     --quote-bg: hsl(197, 37%, 96%);
     --quote-border: hsl(197, 37%, 91%);
 
+    --warning-border: #ff8e00;
+
     --table-border-color: hsl(0, 0%, 95%);
     --table-header-bg: hsl(0, 0%, 80%);
     --table-alternate-bg: hsl(0, 0%, 97%);
@@ -130,6 +142,8 @@
     --searchresults-border-color: #888;
     --searchresults-li-bg: #e4f2fe;
     --search-mark-bg: #a2cff5;
+
+    --color-scheme: light;
 }
 
 .navy {
@@ -158,6 +172,8 @@
     --quote-bg: hsl(226, 15%, 17%);
     --quote-border: hsl(226, 15%, 22%);
 
+    --warning-border: #ff8e00;
+
     --table-border-color: hsl(226, 23%, 16%);
     --table-header-bg: hsl(226, 23%, 31%);
     --table-alternate-bg: hsl(226, 23%, 14%);
@@ -170,6 +186,8 @@
     --searchresults-border-color: #5c5c68;
     --searchresults-li-bg: #242430;
     --search-mark-bg: #a2cff5;
+
+    --color-scheme: dark;
 }
 
 .rust {
@@ -198,6 +216,8 @@
     --quote-bg: hsl(60, 5%, 75%);
     --quote-border: hsl(60, 5%, 70%);
 
+    --warning-border: #ff8e00;
+
     --table-border-color: hsl(60, 9%, 82%);
     --table-header-bg: #b3a497;
     --table-alternate-bg: hsl(60, 9%, 84%);
@@ -210,6 +230,8 @@
     --searchresults-border-color: #888;
     --searchresults-li-bg: #dec2a2;
     --search-mark-bg: #e69f67;
+
+    --color-scheme: light;
 }
 
 @media (prefers-color-scheme: dark) {
@@ -239,6 +261,8 @@
         --quote-bg: hsl(234, 21%, 18%);
         --quote-border: hsl(234, 21%, 23%);
 
+        --warning-border: #ff8e00;
+
         --table-border-color: hsl(200, 7%, 13%);
         --table-header-bg: hsl(200, 7%, 28%);
         --table-alternate-bg: hsl(200, 7%, 11%);

src/theme/index.hbs

@@ -1,11 +1,11 @@
 <!DOCTYPE HTML>
-<html lang="{{ language }}" class="sidebar-visible no-js {{ default_theme }}">
+<html lang="{{ language }}" class="{{ default_theme }}" dir="{{ text_direction }}">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
         <title>{{ title }}</title>
         {{#if is_print }}
-        <meta name="robots" content="noindex" />
+        <meta name="robots" content="noindex">
         {{/if}}
         {{#if base_url}}
         <base href="{{ base_url }}">
@@ -17,7 +17,7 @@
 
         <meta name="description" content="{{ description }}">
         <meta name="viewport" content="width=device-width, initial-scale=1">
-        <meta name="theme-color" content="#ffffff" />
+        <meta name="theme-color" content="#ffffff">
 
         {{#if favicon_svg}}
         <link rel="icon" href="{{ path_to_root }}favicon.svg">
@@ -53,7 +53,7 @@
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
         {{/if}}
     </head>
-    <body>
+    <body class="sidebar-visible no-js">
     <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
@@ -83,31 +83,38 @@
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             var html = document.querySelector('html');
-            html.classList.remove('no-js')
             html.classList.remove('{{ default_theme }}')
             html.classList.add(theme);
-            html.classList.add('js');
+            var body = document.querySelector('body');
+            body.classList.remove('no-js')
+            body.classList.add('js');
         </script>
 
+        <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
+
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var html = document.querySelector('html');
+            var body = document.querySelector('body');
             var sidebar = null;
+            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
             } else {
                 sidebar = 'hidden';
             }
-            html.classList.remove('sidebar-visible');
-            html.classList.add("sidebar-" + sidebar);
+            sidebar_toggle.checked = sidebar === 'visible';
+            body.classList.remove('sidebar-visible');
+            body.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
             <div class="sidebar-scrollbox">
                 {{#toc}}{{/toc}}
             </div>
-            <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
+            <div id="sidebar-resize-handle" class="sidebar-resize-handle">
+                <div class="sidebar-resize-indicator"></div>
+            </div>
         </nav>
 
         <!-- Track and set sidebar scroll position -->
@@ -139,9 +146,9 @@
                 <div id="menu-bar-hover-placeholder"></div>
                 <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">
+                        <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
                             <i class="fa fa-bars"></i>
-                        </button>
+                        </label>
                         <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
                             <i class="fa fa-paint-brush"></i>
                         </button>
@@ -217,7 +224,7 @@
                         {{/previous}}
 
                         {{#next}}
-                            <a rel="next" href="{{ path_to_root }}{{link}}" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                            <a rel="next prefetch" href="{{ path_to_root }}{{link}}" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                                 <i class="fa fa-angle-right"></i>
                             </a>
                         {{/next}}
@@ -235,7 +242,7 @@
                 {{/previous}}
 
                 {{#next}}
-                    <a rel="next" href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                    <a rel="next prefetch" href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                         <i class="fa fa-angle-right"></i>
                     </a>
                 {{/next}}

src/theme/searcher/searcher.js

@@ -316,7 +316,7 @@ window.search = window.search || {};
     
     // Eventhandler for keyevents on `document`
     function globalKeyHandler(e) {
-        if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey || e.target.type === 'textarea' || e.target.type === 'text') { return; }
+        if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey || e.target.type === 'textarea' || e.target.type === 'text' || !hasFocus() && /^(?:input|select|textarea)$/i.test(e.target.nodeName)) { return; }
 
         if (e.keyCode === ESCAPE_KEYCODE) {
             e.preventDefault();

src/utils/fs.rs

@@ -166,7 +166,7 @@ pub fn copy_files_except_ext(
                         .expect("a file should have a file name...")
                 )
             );
-            fs::copy(
+            copy(
                 entry.path(),
                 &to.join(
                     entry
@@ -180,6 +180,62 @@ pub fn copy_files_except_ext(
     Ok(())
 }
 
+/// Copies a file.
+fn copy<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> Result<()> {
+    let from = from.as_ref();
+    let to = to.as_ref();
+    return copy_inner(from, to)
+        .with_context(|| format!("failed to copy `{}` to `{}`", from.display(), to.display()));
+
+    // This is a workaround for an issue with the macOS file watcher.
+    // Rust's `std::fs::copy` function uses `fclonefileat`, which creates
+    // clones on APFS. Unfortunately fs events seem to trigger on both
+    // sides of the clone, and there doesn't seem to be a way to differentiate
+    // which side it is.
+    // https://github.com/notify-rs/notify/issues/465#issuecomment-1657261035
+    // contains more information.
+    //
+    // This is essentially a copy of the simple copy code path in Rust's
+    // standard library.
+    #[cfg(target_os = "macos")]
+    fn copy_inner(from: &Path, to: &Path) -> Result<()> {
+        use std::fs::OpenOptions;
+        use std::os::unix::fs::{OpenOptionsExt, PermissionsExt};
+
+        let mut reader = File::open(from)?;
+        let metadata = reader.metadata()?;
+        if !metadata.is_file() {
+            anyhow::bail!(
+                "expected a file, `{}` appears to be {:?}",
+                from.display(),
+                metadata.file_type()
+            );
+        }
+        let perm = metadata.permissions();
+        let mut writer = OpenOptions::new()
+            .mode(perm.mode())
+            .write(true)
+            .create(true)
+            .truncate(true)
+            .open(to)?;
+        let writer_metadata = writer.metadata()?;
+        if writer_metadata.is_file() {
+            // Set the correct file permissions, in case the file already existed.
+            // Don't set the permissions on already existing non-files like
+            // pipes/FIFOs or device nodes.
+            writer.set_permissions(perm)?;
+        }
+        std::io::copy(&mut reader, &mut writer)?;
+        Ok(())
+    }
+
+    #[cfg(not(target_os = "macos"))]
+    fn copy_inner(from: &Path, to: &Path) -> Result<()> {
+        fs::copy(from, to)?;
+        Ok(())
+    }
+}
+
 pub fn get_404_output_file(input_404: &Option<String>) -> String {
     input_404
         .as_ref()

src/utils/mod.rs

@@ -6,7 +6,7 @@ pub(crate) mod toml_ext;
 use crate::errors::Error;
 use log::error;
 use once_cell::sync::Lazy;
-use pulldown_cmark::{html, CodeBlockKind, CowStr, Event, Options, Parser, Tag};
+use pulldown_cmark::{html, CodeBlockKind, CowStr, Event, Options, Parser, Tag, TagEnd};
 use regex::Regex;
 
 use std::borrow::Cow;
@@ -161,13 +161,30 @@ fn adjust_links<'a>(event: Event<'a>, path: Option<&Path>) -> Event<'a> {
     }
 
     match event {
-        Event::Start(Tag::Link(link_type, dest, title)) => {
-            Event::Start(Tag::Link(link_type, fix(dest, path), title))
-        }
-        Event::Start(Tag::Image(link_type, dest, title)) => {
-            Event::Start(Tag::Image(link_type, fix(dest, path), title))
-        }
+        Event::Start(Tag::Link {
+            link_type,
+            dest_url,
+            title,
+            id,
+        }) => Event::Start(Tag::Link {
+            link_type,
+            dest_url: fix(dest_url, path),
+            title,
+            id,
+        }),
+        Event::Start(Tag::Image {
+            link_type,
+            dest_url,
+            title,
+            id,
+        }) => Event::Start(Tag::Image {
+            link_type,
+            dest_url: fix(dest_url, path),
+            title,
+            id,
+        }),
         Event::Html(html) => Event::Html(fix_html(html, path)),
+        Event::InlineHtml(html) => Event::InlineHtml(fix_html(html, path)),
         _ => event,
     }
 }
@@ -177,7 +194,7 @@ pub fn render_markdown(text: &str, curly_quotes: bool) -> String {
     render_markdown_with_path(text, curly_quotes, None)
 }
 
-pub fn new_cmark_parser(text: &str, curly_quotes: bool) -> Parser<'_, '_> {
+pub fn new_cmark_parser(text: &str, curly_quotes: bool) -> Parser<'_> {
     let mut opts = Options::empty();
     opts.insert(Options::ENABLE_TABLES);
     opts.insert(Options::ENABLE_FOOTNOTES);
@@ -212,7 +229,7 @@ fn wrap_tables(event: Event<'_>) -> (Option<Event<'_>>, Option<Event<'_>>) {
             Some(Event::Html(r#"<div class="table-wrapper">"#.into())),
             Some(event),
         ),
-        Event::End(Tag::Table(_)) => (Some(event), Some(Event::Html(r#"</div>"#.into()))),
+        Event::End(TagEnd::Table) => (Some(event), Some(Event::Html(r#"</div>"#.into()))),
         _ => (Some(event), None),
     }
 }

test_book/src/individual/code.md

@@ -10,7 +10,9 @@ This is a codeblock
 
 ---
 
-This line contains `inline code`
+This line contains `inline code` mixed with some other stuff. (LTR)
+
+ושורה זו מכילה `inline code` אבל עם טקסט בשפה שנכתבת מימין לשמאל. (RTL)
 
 ---
 

test_book/src/languages/README.md

@@ -27,6 +27,7 @@ This Currently contains following languages
 - makefile
 - markdown
 - nginx
+- nim
 - objectivec
 - perl
 - php

test_book/src/languages/highlight.md

@@ -529,6 +529,26 @@ http {
 var doors {.compileTime.}: array[1..numDoors, bool]
 
 proc calcDoors(): string =
+  for pass in 1..numDoors:
+    for door in countup(pass, numDoors, pass):
+      doors[door] = not doors[door]
+  for door in 1..numDoors:
+    result.add("Door $1 is $2.\n" % [$door, if doors[door]: "open" else: "closed"])
+
+const outputString: string = calcDoors()
+
+echo outputString
+```
+
+## objectivec
+
+```objectivec
+#import <Foundation/Foundation.h>
+
+int main(int argc, const char * argv[]) {
+    @mylak {
+        NSLog(@"Hello World!");
+    }
     return 0;
 }
 

tests/alternative_backends.rs

@@ -39,29 +39,27 @@ fn alternate_backend_with_arguments() {
     md.build().unwrap();
 }
 
-/// Get a command which will pipe `stdin` to the provided file.
-#[cfg(not(windows))]
-fn tee_command<P: AsRef<Path>>(out_file: P) -> String {
-    let out_file = out_file.as_ref();
-
-    if cfg!(windows) {
-        format!("cmd.exe /c \"type > {}\"", out_file.display())
-    } else {
-        format!("tee {}", out_file.display())
-    }
-}
-
 #[test]
-#[cfg(not(windows))]
 fn backends_receive_render_context_via_stdin() {
     use mdbook::renderer::RenderContext;
     use std::fs::File;
 
-    let temp = TempFileBuilder::new().prefix("output").tempdir().unwrap();
-    let out_file = temp.path().join("out.txt");
-    let cmd = tee_command(&out_file);
+    let (md, temp) = dummy_book_with_backend("cat-to-file", "renderers/myrenderer", false);
 
-    let (md, _temp) = dummy_book_with_backend("cat-to-file", &cmd, false);
+    let renderers = temp.path().join("renderers");
+    fs::create_dir(&renderers).unwrap();
+    rust_exe(
+        &renderers,
+        "myrenderer",
+        r#"fn main() {
+            use std::io::Read;
+            let mut s = String::new();
+            std::io::stdin().read_to_string(&mut s).unwrap();
+            std::fs::write("out.txt", s).unwrap();
+        }"#,
+    );
+
+    let out_file = temp.path().join("book/out.txt");
 
     assert!(!out_file.exists());
     md.build().unwrap();

tests/dummy_book/src/conclusion.md

@@ -18,3 +18,7 @@ css looks, like this {
 }
 */
 </style>
+
+Sneaky inline event <script>alert("inline");</script>.
+
+But regular <b>inline</b> is indexed.

tests/rendered_output.rs

@@ -375,10 +375,7 @@ fn able_to_include_playground_files_in_chapters() {
 
     let second = temp.path().join("book/second.html");
 
-    let playground_strings = &[
-        r#"class="playground""#,
-        r#"println!("Hello World!");"#,
-    ];
+    let playground_strings = &[r#"class="playground""#, r#"println!("Hello World!");"#];
 
     assert_contains_strings(&second, playground_strings);
     assert_doesnt_contain_strings(&second, &["{{#playground example.rs}}"]);
@@ -745,6 +742,7 @@ mod search {
         let index = read_book_index(temp.path());
 
         let doc_urls = index["doc_urls"].as_array().unwrap();
+        eprintln!("doc_urls={doc_urls:#?}",);
         let get_doc_ref =
             |url: &str| -> String { doc_urls.iter().position(|s| s == url).unwrap().to_string() };
 
@@ -774,7 +772,10 @@ mod search {
             docs[&summary]["breadcrumbs"],
             "First Chapter » Includes » Summary"
         );
-        assert_eq!(docs[&conclusion]["body"], "I put <HTML> in here!");
+        // See note about InlineHtml in search.rs. Ideally the `alert()` part
+        // should not be in the index, but we don't have a way to scrub inline
+        // html.
+        assert_eq!(docs[&conclusion]["body"], "I put <HTML> in here! Sneaky inline event alert(\"inline\");. But regular inline is indexed.");
         assert_eq!(
             docs[&no_headers]["breadcrumbs"],
             "First Chapter » No Headers"

tests/searchindex_fixture.json

@@ -145,7 +145,7 @@
           "title": 1
         },
         "29": {
-          "body": 3,
+          "body": 10,
           "breadcrumbs": 2,
           "title": 1
         },
@@ -319,7 +319,7 @@
           "title": "Some section"
         },
         "29": {
-          "body": "I put <HTML> in here!",
+          "body": "I put <HTML> in here! Sneaky inline event alert(\"inline\");. But regular inline is indexed.",
           "breadcrumbs": "Conclusion » Conclusion",
           "id": "29",
           "title": "Conclusion"
@@ -412,6 +412,54 @@
             },
             "df": 0,
             "docs": {},
+            "l": {
+              "df": 0,
+              "docs": {},
+              "e": {
+                "df": 0,
+                "docs": {},
+                "r": {
+                  "df": 0,
+                  "docs": {},
+                  "t": {
+                    "(": {
+                      "\"": {
+                        "df": 0,
+                        "docs": {},
+                        "i": {
+                          "df": 0,
+                          "docs": {},
+                          "n": {
+                            "df": 0,
+                            "docs": {},
+                            "l": {
+                              "df": 0,
+                              "docs": {},
+                              "i": {
+                                "df": 0,
+                                "docs": {},
+                                "n": {
+                                  "df": 1,
+                                  "docs": {
+                                    "29": {
+                                      "tf": 1.0
+                                    }
+                                  }
+                                }
+                              }
+                            }
+                          }
+                        }
+                      },
+                      "df": 0,
+                      "docs": {}
+                    },
+                    "df": 0,
+                    "docs": {}
+                  }
+                }
+              }
+            },
             "n": {
               "c": {
                 "df": 0,
@@ -1212,6 +1260,14 @@
                     "26": {
                       "tf": 1.0
                     }
+                  },
+                  "t": {
+                    "df": 1,
+                    "docs": {
+                      "29": {
+                        "tf": 1.0
+                      }
+                    }
                   }
                 }
               }
@@ -1684,10 +1740,13 @@
                   "df": 0,
                   "docs": {},
                   "x": {
-                    "df": 1,
+                    "df": 2,
                     "docs": {
                       "0": {
                         "tf": 1.0
+                      },
+                      "29": {
+                        "tf": 1.0
                       }
                     }
                   }
@@ -1695,6 +1754,22 @@
               },
               "df": 0,
               "docs": {},
+              "l": {
+                "df": 0,
+                "docs": {},
+                "i": {
+                  "df": 0,
+                  "docs": {},
+                  "n": {
+                    "df": 1,
+                    "docs": {
+                      "29": {
+                        "tf": 1.4142135623730951
+                      }
+                    }
+                  }
+                }
+              },
               "s": {
                 "df": 0,
                 "docs": {},
@@ -2359,6 +2434,30 @@
               },
               "df": 0,
               "docs": {},
+              "g": {
+                "df": 0,
+                "docs": {},
+                "u": {
+                  "df": 0,
+                  "docs": {},
+                  "l": {
+                    "a": {
+                      "df": 0,
+                      "docs": {},
+                      "r": {
+                        "df": 1,
+                        "docs": {
+                          "29": {
+                            "tf": 1.0
+                          }
+                        }
+                      }
+                    },
+                    "df": 0,
+                    "docs": {}
+                  }
+                }
+              },
               "l": {
                 "df": 1,
                 "docs": {
@@ -2590,6 +2689,26 @@
             "n": {
               "df": 0,
               "docs": {},
+              "e": {
+                "a": {
+                  "df": 0,
+                  "docs": {},
+                  "k": {
+                    "df": 0,
+                    "docs": {},
+                    "i": {
+                      "df": 1,
+                      "docs": {
+                        "29": {
+                          "tf": 1.0
+                        }
+                      }
+                    }
+                  }
+                },
+                "df": 0,
+                "docs": {}
+              },
               "i": {
                 "df": 0,
                 "docs": {},
@@ -3252,6 +3371,54 @@
             },
             "df": 0,
             "docs": {},
+            "l": {
+              "df": 0,
+              "docs": {},
+              "e": {
+                "df": 0,
+                "docs": {},
+                "r": {
+                  "df": 0,
+                  "docs": {},
+                  "t": {
+                    "(": {
+                      "\"": {
+                        "df": 0,
+                        "docs": {},
+                        "i": {
+                          "df": 0,
+                          "docs": {},
+                          "n": {
+                            "df": 0,
+                            "docs": {},
+                            "l": {
+                              "df": 0,
+                              "docs": {},
+                              "i": {
+                                "df": 0,
+                                "docs": {},
+                                "n": {
+                                  "df": 1,
+                                  "docs": {
+                                    "29": {
+                                      "tf": 1.0
+                                    }
+                                  }
+                                }
+                              }
+                            }
+                          }
+                        }
+                      },
+                      "df": 0,
+                      "docs": {}
+                    },
+                    "df": 0,
+                    "docs": {}
+                  }
+                }
+              }
+            },
             "n": {
               "c": {
                 "df": 0,
@@ -4130,6 +4297,14 @@
                     "26": {
                       "tf": 1.0
                     }
+                  },
+                  "t": {
+                    "df": 1,
+                    "docs": {
+                      "29": {
+                        "tf": 1.0
+                      }
+                    }
                   }
                 }
               }
@@ -4665,10 +4840,13 @@
                   "df": 0,
                   "docs": {},
                   "x": {
-                    "df": 1,
+                    "df": 2,
                     "docs": {
                       "0": {
                         "tf": 1.0
+                      },
+                      "29": {
+                        "tf": 1.0
                       }
                     }
                   }
@@ -4676,6 +4854,22 @@
               },
               "df": 0,
               "docs": {},
+              "l": {
+                "df": 0,
+                "docs": {},
+                "i": {
+                  "df": 0,
+                  "docs": {},
+                  "n": {
+                    "df": 1,
+                    "docs": {
+                      "29": {
+                        "tf": 1.4142135623730951
+                      }
+                    }
+                  }
+                }
+              },
               "s": {
                 "df": 0,
                 "docs": {},
@@ -5373,6 +5567,30 @@
               },
               "df": 0,
               "docs": {},
+              "g": {
+                "df": 0,
+                "docs": {},
+                "u": {
+                  "df": 0,
+                  "docs": {},
+                  "l": {
+                    "a": {
+                      "df": 0,
+                      "docs": {},
+                      "r": {
+                        "df": 1,
+                        "docs": {
+                          "29": {
+                            "tf": 1.0
+                          }
+                        }
+                      }
+                    },
+                    "df": 0,
+                    "docs": {}
+                  }
+                }
+              },
               "l": {
                 "df": 1,
                 "docs": {
@@ -5610,6 +5828,26 @@
             "n": {
               "df": 0,
               "docs": {},
+              "e": {
+                "a": {
+                  "df": 0,
+                  "docs": {},
+                  "k": {
+                    "df": 0,
+                    "docs": {},
+                    "i": {
+                      "df": 1,
+                      "docs": {
+                        "29": {
+                          "tf": 1.0
+                        }
+                      }
+                    }
+                  }
+                },
+                "df": 0,
+                "docs": {}
+              },
               "i": {
                 "df": 0,
                 "docs": {},