From 6163d892248a2af02b36a0121bb5bf02a5566d2b Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sat, 26 Sep 2020 15:18:38 +0200
Subject: [PATCH] Improve code

---
 src/librustdoc/passes/html_tags.rs           | 22 +++++++++-----
 src/test/rustdoc-ui/invalid-html-tags.rs     | 19 +++++++++++++
 src/test/rustdoc-ui/invalid-html-tags.stderr | 30 ++++++++++++++++----
 3 files changed, 58 insertions(+), 13 deletions(-)

diff --git a/src/librustdoc/passes/html_tags.rs b/src/librustdoc/passes/html_tags.rs
index dfc5373886a..79035ba79ff 100644
--- a/src/librustdoc/passes/html_tags.rs
+++ b/src/librustdoc/passes/html_tags.rs
@@ -45,18 +45,20 @@ fn drop_tag(
     range: Range<usize>,
     f: &impl Fn(&str, &Range<usize>),
 ) {
-    if let Some(pos) = tags.iter().position(|(t, _)| *t == tag_name) {
-        for _ in pos + 1..tags.len() {
-            if ALLOWED_UNCLOSED.iter().find(|&at| at == &tags[pos + 1].0).is_some() {
+    if let Some(pos) = tags.iter().rev().position(|(t, _)| *t == tag_name) {
+        // Because this is from a `rev` iterator, the position is reversed as well!
+        let pos = tags.len() - 1 - pos;
+        for (last_tag_name, last_tag_span) in tags.drain(pos + 1..) {
+            if ALLOWED_UNCLOSED.iter().any(|&at| at == &last_tag_name) {
                 continue;
             }
             // `tags` is used as a queue, meaning that everything after `pos` is included inside it.
             // So `<h2><h3></h2>` will look like `["h2", "h3"]`. So when closing `h2`, we will still
             // have `h3`, meaning the tag wasn't closed as it should have.
-            f(&format!("unclosed HTML tag `{}`", tags[pos + 1].0), &tags[pos + 1].1);
-            tags.remove(pos + 1);
+            f(&format!("unclosed HTML tag `{}`", last_tag_name), &last_tag_span);
         }
-        tags.remove(pos);
+        // Remove the `tag_name` that was originally closed
+        tags.pop();
     } else {
         // It can happen for example in this case: `<h2></script></h2>` (the `h2` tag isn't required
         // but it helps for the visualization).
@@ -84,7 +86,13 @@ fn extract_tag(
                     tag_name.push(*c);
                 } else {
                     if !tag_name.is_empty() {
-                        let r = Range { start: range.start + start_pos, end: range.start + pos };
+                        let mut r =
+                            Range { start: range.start + start_pos, end: range.start + pos };
+                        if *c == '>' {
+                            // In case we have a tag without attribute, we can consider the span to
+                            // refer to it fully.
+                            r.end += 1;
+                        }
                         if is_closing {
                             drop_tag(tags, tag_name, r, f);
                         } else {
diff --git a/src/test/rustdoc-ui/invalid-html-tags.rs b/src/test/rustdoc-ui/invalid-html-tags.rs
index b188e16f605..51bbae2a0b6 100644
--- a/src/test/rustdoc-ui/invalid-html-tags.rs
+++ b/src/test/rustdoc-ui/invalid-html-tags.rs
@@ -20,3 +20,22 @@ pub fn foo() {}
 /// </hello>
 //~^ ERROR unopened HTML tag `hello`
 pub fn f() {}
+
+/// <div>
+///    <br/> <p>
+//~^ ERROR unclosed HTML tag `p`
+/// </div>
+pub fn a() {}
+
+/// <div>
+///   <p>
+///      <div></div>
+///   </p>
+/// </div>
+pub fn b() {}
+
+/// <div style="hello">
+//~^ ERROR unclosed HTML tag `div`
+///   <h3>
+//~^ ERROR unclosed HTML tag `h3`
+pub fn c() {}
diff --git a/src/test/rustdoc-ui/invalid-html-tags.stderr b/src/test/rustdoc-ui/invalid-html-tags.stderr
index f8e67732f63..d2e9704a227 100644
--- a/src/test/rustdoc-ui/invalid-html-tags.stderr
+++ b/src/test/rustdoc-ui/invalid-html-tags.stderr
@@ -2,7 +2,7 @@ error: unclosed HTML tag `unknown`
   --> $DIR/invalid-html-tags.rs:7:5
    |
 LL | /// <unknown>
-   |     ^^^^^^^^
+   |     ^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/invalid-html-tags.rs:1:9
@@ -14,25 +14,43 @@ error: unclosed HTML tag `script`
   --> $DIR/invalid-html-tags.rs:10:5
    |
 LL | /// <script>
-   |     ^^^^^^^
+   |     ^^^^^^^^
 
 error: unclosed HTML tag `h2`
   --> $DIR/invalid-html-tags.rs:15:7
    |
 LL | ///   <h2>
-   |       ^^^
+   |       ^^^^
 
 error: unclosed HTML tag `h3`
   --> $DIR/invalid-html-tags.rs:17:9
    |
 LL | ///     <h3>
-   |         ^^^
+   |         ^^^^
 
 error: unopened HTML tag `hello`
   --> $DIR/invalid-html-tags.rs:20:5
    |
 LL | /// </hello>
-   |     ^^^^^^^
+   |     ^^^^^^^^
+
+error: unclosed HTML tag `p`
+  --> $DIR/invalid-html-tags.rs:25:14
+   |
+LL | ///    <br/> <p>
+   |              ^^^
+
+error: unclosed HTML tag `div`
+  --> $DIR/invalid-html-tags.rs:37:5
+   |
+LL | /// <div style="hello">
+   |     ^^^^
+
+error: unclosed HTML tag `h3`
+  --> $DIR/invalid-html-tags.rs:39:7
+   |
+LL | ///   <h3>
+   |       ^^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 8 previous errors
 
-- 
2.44.0