From 20eda22cbf36b5e9bf9fe28c53790c30fb31c9d3 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume.gomez@huawei.com>
Date: Thu, 25 Nov 2021 15:33:38 +0100
Subject: [PATCH 1/2] Update the first heading indent rule so it is only
 applied on the first heading of the top doc block

---
 src/librustdoc/html/static/css/rustdoc.css | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index bfad510695131..479b5210f9e09 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1129,15 +1129,17 @@ h3.variant {
 	margin-top: 3px;
 }
 
-.docblock > .section-header:first-child {
+.top-doc .docblock > .section-header:first-child {
 	margin-left: 15px;
-	margin-top: 0;
 }
-
-.docblock > .section-header:first-child:hover > a:before {
+.top-doc .docblock > .section-header:first-child:hover > a:before {
 	left: -10px;
 }
 
+.docblock > .section-header:first-child {
+	margin-top: 0;
+}
+
 :target > code, :target > .code-header {
 	opacity: 1;
 }

From 23427567b2030dfe1a8e99cd86d2602517118035 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume.gomez@huawei.com>
Date: Thu, 25 Nov 2021 15:39:04 +0100
Subject: [PATCH 2/2] Update test for anchors and headings position

---
 src/test/rustdoc-gui/anchors.goml         | 46 ++++++++++++++++++++++-
 src/test/rustdoc-gui/src/test_docs/lib.rs |  2 +
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/test/rustdoc-gui/anchors.goml b/src/test/rustdoc-gui/anchors.goml
index 5f809f9aa4ed4..8910cbbbb256c 100644
--- a/src/test/rustdoc-gui/anchors.goml
+++ b/src/test/rustdoc-gui/anchors.goml
@@ -1,4 +1,4 @@
-// This test is to ensure that the anchors (`§`) have the expected color.
+// This test is to ensure that the anchors (`§`) have the expected color and position.
 goto: file://|DOC_PATH|/test_docs/struct.HeavilyDocumentedStruct.html
 show-text: true
 
@@ -28,3 +28,47 @@ assert-css: ("h2#implementations a.anchor", {"color": "rgb(0, 0, 0)"})
 // Same thing with the impl block title.
 move-cursor-to: "#impl"
 assert-css: ("#impl a.anchor", {"color": "rgb(0, 0, 0)"})
+
+// Now we check the positions: only the first heading of the top doc comment should
+// have a different position.
+move-cursor-to: ".top-doc .docblock .section-header:first-child"
+assert-css: (
+    ".top-doc .docblock .section-header:first-child > a::before",
+    {"left": "-10px", "padding-right": "10px"}
+)
+// We also check that the heading itself has a different indent.
+assert-css: (".top-doc .docblock .section-header:first-child", {"margin-left": "15px"})
+
+move-cursor-to: ".top-doc .docblock .section-header:not(:first-child)"
+assert-css: (
+    ".top-doc .docblock .section-header:not(:first-child) > a::before",
+    {"left": "-25px", "padding-right": "10px"}
+)
+assert-css: (".top-doc .docblock .section-header:not(:first-child)", {"margin-left": "0px"})
+
+// Now let's check some other docblock headings...
+// First the impl block docs.
+move-cursor-to: "#title-for-struct-impl-doc"
+assert-css: (
+    "#title-for-struct-impl-doc > a::before",
+    {"left": "-25px", "padding-right": "10px"}
+)
+assert-css: ("#title-for-struct-impl-doc", {"margin-left": "0px"})
+// Now a method docs.
+move-cursor-to: "#title-for-struct-impl-item-doc"
+assert-css: (
+    "#title-for-struct-impl-item-doc > a::before",
+    {"left": "-25px", "padding-right": "10px"}
+)
+assert-css: ("#title-for-struct-impl-item-doc", {"margin-left": "0px"})
+
+// Finally, we want to ensure that if the first element of the doc block isn't a heading,
+// if there is a heading afterwards, it won't have the indent.
+goto: file://|DOC_PATH|/test_docs/enum.WhoLetTheDogOut.html
+
+move-cursor-to: ".top-doc .docblock .section-header"
+assert-css: (
+    ".top-doc .docblock .section-header > a::before",
+    {"left": "-25px", "padding-right": "10px"}
+)
+assert-css: (".top-doc .docblock .section-header", {"margin-left": "0px"})
diff --git a/src/test/rustdoc-gui/src/test_docs/lib.rs b/src/test/rustdoc-gui/src/test_docs/lib.rs
index 458bcc4780c6c..9b37703dded4b 100644
--- a/src/test/rustdoc-gui/src/test_docs/lib.rs
+++ b/src/test/rustdoc-gui/src/test_docs/lib.rs
@@ -47,6 +47,8 @@ impl AsRef<str> for Foo {
 }
 
 /// Just a normal enum.
+///
+/// # title!
 #[doc(alias = "ThisIsAnAlias")]
 pub enum WhoLetTheDogOut {
     /// Woof!