From 5ebbed6cb02fb4d0272a0b86c500d8f668de321d Mon Sep 17 00:00:00 2001
From: Jacob Hoffman-Andrews <github@hoffman-andrews.com>
Date: Fri, 21 May 2021 21:24:03 -0700
Subject: [PATCH] Fix auto-hide for implementations and implementors.

This sets their toggles to be closed in the HTML (matching the default
setting), and opens them if the setting indicates to do so.

This distinguishes between implementations and implementors based on
being descendants of certain named elements.
---
 src/librustdoc/html/render/mod.rs  |  2 +-
 src/librustdoc/html/static/main.js | 25 +++++++++++++++++++++----
 src/test/rustdoc/manual_impl.rs    |  3 ++-
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 318e1b44f86..b3bd1cd0121 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -1545,7 +1545,7 @@ fn render_default_items(
     let open_details = |close_tags: &mut String| {
         if toggled {
             close_tags.insert_str(0, "</details>");
-            "<details class=\"rustdoc-toggle implementors-toggle\" open><summary>"
+            "<details class=\"rustdoc-toggle implementors-toggle\"><summary>"
         } else {
             ""
         }
diff --git a/src/librustdoc/html/static/main.js b/src/librustdoc/html/static/main.js
index 1e28056bb68..a96b0c87108 100644
--- a/src/librustdoc/html/static/main.js
+++ b/src/librustdoc/html/static/main.js
@@ -776,12 +776,29 @@ function hideThemeButtonState() {
 
         var hideMethodDocs = getSettingValue("auto-hide-method-docs") === "true";
         var hideImplementors = getSettingValue("auto-collapse-implementors") !== "false";
+        var hideImplementations = getSettingValue("auto-hide-trait-implementations") !== "false";
         var hideLargeItemContents = getSettingValue("auto-hide-large-items") !== "false";
 
-        onEachLazy(document.getElementsByTagName("details"), function (e) {
-            var showLargeItem = !hideLargeItemContents && hasClass(e, "type-contents-toggle");
-            var showImplementor = !hideImplementors && hasClass(e, "implementors-toggle");
-            if (showLargeItem || showImplementor) {
+        function openImplementors(id) {
+            var list = document.getElementById(id);
+            if (list !== null) {
+                onEachLazy(list.getElementsByClassName("implementors-toggle"), function(e) {
+                    e.open = true;
+                });
+            }
+        }
+
+        if (!hideImplementations) {
+            openImplementors("trait-implementations-list");
+            openImplementors("blanket-implementations-list");
+        }
+
+        if (!hideImplementors) {
+            openImplementors("implementors-list");
+        }
+
+        onEachLazy(document.getElementsByClassName("rustdoc-toggle"), function (e) {
+            if (!hideLargeItemContents && hasClass(e, "type-contents-toggle")) {
                 e.open = true;
             }
             if (hideMethodDocs && hasClass(e, "method-toggle")) {
diff --git a/src/test/rustdoc/manual_impl.rs b/src/test/rustdoc/manual_impl.rs
index 776a191ceef..5b448bd1923 100644
--- a/src/test/rustdoc/manual_impl.rs
+++ b/src/test/rustdoc/manual_impl.rs
@@ -65,7 +65,8 @@ fn c_method(&self) -> usize {
 }
 
 // @has manual_impl/struct.S3.html '//*[@class="trait"]' 'T'
-// @has  - '//details[@open=""]/div[@class="docblock"]' 'Docs associated with the S3 trait implementation.'
+// @has  - '//details/div[@class="docblock"]' 'Docs associated with the S3 trait implementation.'
+// @!has  - '//details[@open=""]/div[@class="docblock"]' 'Docs associated with the S3 trait implementation.'
 // @has  - '//details[@open=""]/div[@class="docblock"]' 'Docs associated with the S3 trait b_method implementation.'
 // @!has - '//div[@class="impl-items"]/details[@open=""]//div[@class="docblock"]' 'Docs associated with the trait a_method definition.'
 // @has - '//div[@class="impl-items"]/details//div[@class="docblock"]' 'Docs associated with the trait a_method definition.'