Fix dest-dir command-line flag.

src/cmd/serve.rs

@@ -63,15 +63,17 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     let address = format!("{}:{}", hostname, port);
 
     let livereload_url = format!("ws://{}/{}", address, LIVE_RELOAD_ENDPOINT);
-    book.config
-        .set("output.html.livereload-url", &livereload_url)?;
-
-    if let Some(dest_dir) = args.value_of("dest-dir") {
-        book.config.build.build_dir = dest_dir.into();
-    }
-    // Override site-url for local serving of the 404 file
-    book.config.set("output.html.site-url", "/")?;
-
+    let update_config = |book: &mut MDBook| {
+        book.config
+            .set("output.html.livereload-url", &livereload_url)
+            .expect("livereload-url update failed");
+        if let Some(dest_dir) = args.value_of("dest-dir") {
+            book.config.build.build_dir = dest_dir.into();
+        }
+        // Override site-url for local serving of the 404 file
+        book.config.set("output.html.site-url", "/").unwrap();
+    };
+    update_config(&mut book);
     book.build()?;
 
     let sockaddr: SocketAddr = address
@@ -108,13 +110,10 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
         info!("Building book...");
 
         // FIXME: This area is really ugly because we need to re-set livereload :(
-        let result = MDBook::load(&book_dir)
-            .and_then(|mut b| {
-                b.config
-                    .set("output.html.livereload-url", &livereload_url)?;
-                Ok(b)
-            })
-            .and_then(|b| b.build());
+        let result = MDBook::load(&book_dir).and_then(|mut b| {
+            update_config(&mut b);
+            b.build()
+        });
 
         if let Err(e) = result {
             error!("Unable to load the book");

src/cmd/watch.rs

@@ -28,7 +28,14 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
 // Watch command implementation
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
-    let book = MDBook::load(&book_dir)?;
+    let mut book = MDBook::load(&book_dir)?;
+
+    let update_config = |book: &mut MDBook| {
+        if let Some(dest_dir) = args.value_of("dest-dir") {
+            book.config.build.build_dir = dest_dir.into();
+        }
+    };
+    update_config(&mut book);
 
     if args.is_present("open") {
         book.build()?;
@@ -37,7 +44,10 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
 
     trigger_on_change(&book, |paths, book_dir| {
         info!("Files changed: {:?}\nBuilding book...\n", paths);
-        let result = MDBook::load(&book_dir).and_then(|b| b.build());
+        let result = MDBook::load(&book_dir).and_then(|mut b| {
+            update_config(&mut b);
+            b.build()
+        });
 
         if let Err(e) = result {
             error!("Unable to build the book");

src/renderer/html_handlebars/hbs_renderer.rs

@@ -151,7 +151,8 @@ impl HtmlHandlebars {
         data_404.insert("content".to_owned(), json!(html_content_404));
         let rendered = handlebars.render("index", &data_404)?;
 
-        let rendered = self.post_process(rendered, &html_config.playpen, ctx.config.rust.edition);
+        let rendered =
+            self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
         let output_file = get_404_output_file(&html_config.input_404);
         utils::fs::write_file(&destination, output_file, rendered.as_bytes())?;
         debug!("Creating 404.html ✓");