From 7986bb8c463ea6c61788983e4016243bef97acdc Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Mon, 16 Nov 2020 15:31:35 +0100
Subject: [PATCH 1/2] Don't warn about invalid HTML tags in code blocks

---
 src/librustdoc/passes/html_tags.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/librustdoc/passes/html_tags.rs b/src/librustdoc/passes/html_tags.rs
index 26b64b4905ea7..bfe53d63960b1 100644
--- a/src/librustdoc/passes/html_tags.rs
+++ b/src/librustdoc/passes/html_tags.rs
@@ -4,7 +4,7 @@ use crate::core::DocContext;
 use crate::fold::DocFolder;
 use crate::html::markdown::opts;
 use core::ops::Range;
-use pulldown_cmark::{Event, Parser};
+use pulldown_cmark::{Event, Parser, Tag};
 use rustc_session::lint;
 use std::iter::Peekable;
 use std::str::CharIndices;
@@ -196,14 +196,17 @@ impl<'a, 'tcx> DocFolder for InvalidHtmlTagsLinter<'a, 'tcx> {
 
             let mut tags = Vec::new();
             let mut is_in_comment = None;
+            let mut in_code_block = false;
 
             let p = Parser::new_ext(&dox, opts()).into_offset_iter();
 
             for (event, range) in p {
                 match event {
-                    Event::Html(text) | Event::Text(text) => {
+                    Event::Start(Tag::CodeBlock(_)) => in_code_block = true,
+                    Event::Html(text) | Event::Text(text) if !in_code_block => {
                         extract_tags(&mut tags, &text, range, &mut is_in_comment, &report_diag)
                     }
+                    Event::End(Tag::CodeBlock(_)) => in_code_block = false,
                     _ => {}
                 }
             }

From bbd302bab469a1da3804a4b998817ccbf15c874e Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Mon, 16 Nov 2020 15:32:26 +0100
Subject: [PATCH 2/2] Add test to ensure that "invalid HTML tag" lint isn't
 fired in code blocks

---
 src/test/rustdoc-ui/invalid-html-tags.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/test/rustdoc-ui/invalid-html-tags.rs b/src/test/rustdoc-ui/invalid-html-tags.rs
index 56ca7e79d4358..9c2fc4beb5eb1 100644
--- a/src/test/rustdoc-ui/invalid-html-tags.rs
+++ b/src/test/rustdoc-ui/invalid-html-tags.rs
@@ -87,3 +87,24 @@ pub fn h() {}
 /// <!--
 //~^ ERROR Unclosed HTML comment
 pub fn i() {}
+
+/// hello
+///
+/// ```
+/// uiapp.run(&env::args().collect::<Vec<_>>());
+/// ```
+pub fn j() {}
+
+// Check that nested codeblocks are working as well
+/// hello
+///
+/// ``````markdown
+/// normal markdown
+///
+/// ```
+/// uiapp.run(&env::args().collect::<Vec<_>>());
+/// ```
+///
+/// <Vec<_> shouldn't warn!
+/// ``````
+pub fn k() {}