Add go_to_first query param to jump to first result

src/doc/rustdoc/src/SUMMARY.md

@@ -10,5 +10,6 @@
 - [Lints](lints.md)
 - [Advanced features](advanced-features.md)
 - [Unstable features](unstable-features.md)
+- [Website features](website-features.md)
 - [Passes](passes.md)
 - [References](references.md)

src/doc/rustdoc/src/website-features.md

@@ -0,0 +1,25 @@
+# Website features
+
+These features are about using the website generated by `rustdoc`.
+
+## Custom search engines
+
+If you find yourself often referencing online Rust docs you might enjoy using a custom search
+engine. This allows you to use the navigation bar directly to search a `rustdoc` website.
+Most browsers support this feature by letting you define a URL template containing `%s`
+which will be substituted for the search term. As an example, for the standard library you could use
+this template:
+
+```text
+https://doc.rust-lang.org/stable/std/?search=%s
+```
+
+Note that this will take you to a results page listing all matches. If you want to navigate to the first
+result right away (which is often the best match) use the following instead:
+
+```text
+https://doc.rust-lang.org/stable/std/?search=%s&go_to_first=true
+```
+
+This URL adds the `go_to_first=true` query parameter which can be appended to any `rustdoc` search URL
+to automatically go to the first result.

src/librustdoc/html/static/search.js

@@ -1058,14 +1058,14 @@ window.initSearch = function(rawSearchIndex) {
  return "<button>" + text + " <div class=\"count\">(" + nbElems + ")</div></button>";
  }
 
- function showResults(results) {
+ function showResults(results, go_to_first) {
  var search = searchState.outputElement();
- if (results.others.length === 1
+ if (go_to_first || (results.others.length === 1
  && getSettingValue("go-to-only-result") === "true"
  // By default, the search DOM element is "empty" (meaning it has no children not
  // text content). Once a search has been run, it won't be empty, even if you press
  // ESC or empty the search input (which also "cancels" the search).
- && (!search.firstChild || search.firstChild.innerText !== searchState.loadingText))
+ && (!search.firstChild || search.firstChild.innerText !== searchState.loadingText)))
  {
  var elem = document.createElement("a");
  elem.href = results.others[0].href;
@@ -1242,7 +1242,7 @@ window.initSearch = function(rawSearchIndex) {
  }
 
  var filterCrates = getFilterCrates();
- showResults(execSearch(query, index, filterCrates));
+ showResults(execSearch(query, index, filterCrates), params.go_to_first);
  }
 
  function buildIndex(rawSearchIndex) {