Rework doc blocks headings by not turning them into links anymore and putting an anchor to their left side

Author: GuillaumeGomez

src/librustdoc/html/markdown.rs

@@ -560,14 +560,10 @@ impl<'a, 'b, 'ids, I: Iterator<Item = SpannedEvent<'a>>> Iterator
 
             let level =
                 std::cmp::min(level as u32 + (self.heading_offset as u32), MAX_HEADER_LEVEL);
-            self.buf.push_back((Event::Html(format!("</a></h{}>", level).into()), 0..0));
-
-            let start_tags = format!(
-                "<h{level} id=\"{id}\">\
-                    <a href=\"#{id}\">",
-                id = id,
-                level = level
-            );
+            self.buf.push_back((Event::Html(format!("</h{level}>").into()), 0..0));
+
+            let start_tags =
+                format!("<h{level} id=\"{id}\"><a class=\"doc-anchor\" href=\"#{id}\">§</a>");
             return Some((Event::Html(start_tags.into()), 0..0));
         }
         event

src/librustdoc/html/markdown/tests.rs

@@ -159,24 +159,29 @@ fn test_header() {
         assert_eq!(output, expect, "original: {}", input);
     }
 
-    t("# Foo bar", "<h2 id=\"foo-bar\"><a href=\"#foo-bar\">Foo bar</a></h2>");
+    t(
+        "# Foo bar",
+        "<h2 id=\"foo-bar\"><a class=\"doc-anchor\" href=\"#foo-bar\">§</a>Foo bar</h2>",
+    );
     t(
         "## Foo-bar_baz qux",
         "<h3 id=\"foo-bar_baz-qux\">\
-         <a href=\"#foo-bar_baz-qux\">Foo-bar_baz qux</a></h3>",
+             <a class=\"doc-anchor\" href=\"#foo-bar_baz-qux\">§</a>\
+             Foo-bar_baz qux\
+         </h3>",
     );
     t(
         "### **Foo** *bar* baz!?!& -_qux_-%",
         "<h4 id=\"foo-bar-baz--qux-\">\
-            <a href=\"#foo-bar-baz--qux-\"><strong>Foo</strong> \
-            <em>bar</em> baz!?!&amp; -<em>qux</em>-%</a>\
+            <a class=\"doc-anchor\" href=\"#foo-bar-baz--qux-\">§</a>\
+            <strong>Foo</strong> <em>bar</em> baz!?!&amp; -<em>qux</em>-%\
          </h4>",
     );
     t(
         "#### **Foo?** & \\*bar?!*  _`baz`_ ❤ #qux",
         "<h5 id=\"foo--bar--baz--qux\">\
-             <a href=\"#foo--bar--baz--qux\"><strong>Foo?</strong> &amp; *bar?!*  \
-             <em><code>baz</code></em> ❤ #qux</a>\
+             <a class=\"doc-anchor\" href=\"#foo--bar--baz--qux\">§</a>\
+             <strong>Foo?</strong> &amp; *bar?!*  <em><code>baz</code></em> ❤ #qux\
          </h5>",
     );
 }
@@ -198,12 +203,36 @@ fn test_header_ids_multiple_blocks() {
         assert_eq!(output, expect, "original: {}", input);
     }
 
-    t(&mut map, "# Example", "<h2 id=\"example\"><a href=\"#example\">Example</a></h2>");
-    t(&mut map, "# Panics", "<h2 id=\"panics\"><a href=\"#panics\">Panics</a></h2>");
-    t(&mut map, "# Example", "<h2 id=\"example-1\"><a href=\"#example-1\">Example</a></h2>");
-    t(&mut map, "# Search", "<h2 id=\"search-1\"><a href=\"#search-1\">Search</a></h2>");
-    t(&mut map, "# Example", "<h2 id=\"example-2\"><a href=\"#example-2\">Example</a></h2>");
-    t(&mut map, "# Panics", "<h2 id=\"panics-1\"><a href=\"#panics-1\">Panics</a></h2>");
+    t(
+        &mut map,
+        "# Example",
+        "<h2 id=\"example\"><a class=\"doc-anchor\" href=\"#example\">§</a>Example</h2>",
+    );
+    t(
+        &mut map,
+        "# Panics",
+        "<h2 id=\"panics\"><a class=\"doc-anchor\" href=\"#panics\">§</a>Panics</h2>",
+    );
+    t(
+        &mut map,
+        "# Example",
+        "<h2 id=\"example-1\"><a class=\"doc-anchor\" href=\"#example-1\">§</a>Example</h2>",
+    );
+    t(
+        &mut map,
+        "# Search",
+        "<h2 id=\"search-1\"><a class=\"doc-anchor\" href=\"#search-1\">§</a>Search</h2>",
+    );
+    t(
+        &mut map,
+        "# Example",
+        "<h2 id=\"example-2\"><a class=\"doc-anchor\" href=\"#example-2\">§</a>Example</h2>",
+    );
+    t(
+        &mut map,
+        "# Panics",
+        "<h2 id=\"panics-1\"><a class=\"doc-anchor\" href=\"#panics-1\">§</a>Panics</h2>",
+    );
 }
 
 #[test]

src/librustdoc/html/static/css/rustdoc.css

@@ -833,6 +833,9 @@ h2.small-section-header > .anchor {
 .anchor::before {
 	content: '§';
 }
+.doc-anchor {
+	margin-right: 6px;
+}
 
 .docblock a:not(.srclink):not(.test-arrow):hover,
 .docblock-short a:not(.srclink):not(.test-arrow):hover, .item-info a {