Fix error-index redirect to work with back button.

ehuss · ehuss · commit f2ad85a93053 · 2023-01-05T11:07:11.000-08:00
diff --git a/src/tools/error_index_generator/main.rs b/src/tools/error_index_generator/main.rs
@@ -98,8 +98,7 @@ fn add_rust_attribute_on_codeblock(explanation: &str) -> String {
 
 fn render_html(output_path: &Path) -> Result<(), Box<dyn Error>> {
     let mut introduction = format!(
-        "<script src='redirect.js'></script>
-# Rust error codes index
+        "# Rust error codes index
 
 This page lists all the error codes emitted by the Rust compiler.
 
@@ -149,7 +148,12 @@ This page lists all the error codes emitted by the Rust compiler.
     book.book.sections.push(BookItem::Chapter(chapter));
     book.build()?;
 
-    // We can't put this content into another file, otherwise `mbdbook` will also put it into the
+    // The error-index used to be generated manually (without mdbook), and the
+    // index was located at the top level. Now that it is generated with
+    // mdbook, error-index.html has moved to error_codes/error-index.html.
+    // This adds a redirect so that old links go to the new location.
+    //
+    // We can't put this content into another file, otherwise `mdbook` will also put it into the
     // output directory, making a duplicate.
     fs::write(
         output_path.join("error-index.html"),
@@ -163,7 +167,6 @@ This page lists all the error codes emitted by the Rust compiler.
     </head>
     <body>
         <div>If you are not automatically redirected to the error code index, please <a id="index-link" href="./error_codes/error-index.html">here</a>.
-        <script>document.getElementById("index-link").click()</script>
     </body>
 </html>"#,
     )?;
diff --git a/src/tools/error_index_generator/redirect.js b/src/tools/error_index_generator/redirect.js
@@ -3,14 +3,10 @@
         let code = window.location.hash.replace(/^#/, '');
         // We have to make sure this pattern matches to avoid inadvertently creating an
         // open redirect.
-        if (!/^E[0-9]+$/.test(code)) {
+        if (/^E[0-9]+$/.test(code)) {
+            window.location.replace('./error_codes/' + code + '.html');
             return;
         }
-        if (window.location.pathname.indexOf("/error_codes/") !== -1) {
-            // We're not at the top level, so we don't prepend with "./error_codes/".
-            window.location = './' + code + '.html';
-        } else {
-            window.location = './error_codes/' + code + '.html';
-        }
     }
+    window.location.replace('./error_codes/error-index.html');
 })()
