From ca199b16e5c06c28b3d35de79ffaaff81bd0d43f Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sat, 3 Oct 2020 15:43:04 +0200
Subject: [PATCH] Use char_indices() instead of chars() to prevent more than
 one-byte characters issue

---
 src/librustdoc/passes/html_tags.rs           | 21 +++-------
 src/test/rustdoc-ui/intra-link-errors.rs     |  1 -
 src/test/rustdoc-ui/intra-link-errors.stderr | 42 ++++++++++----------
 src/test/rustdoc-ui/invalid-html-tags.rs     |  1 +
 src/test/rustdoc-ui/invalid-html-tags.stderr | 26 +++++++-----
 5 files changed, 43 insertions(+), 48 deletions(-)

diff --git a/src/librustdoc/passes/html_tags.rs b/src/librustdoc/passes/html_tags.rs
index f8869a41eb6..4218717c436 100644
--- a/src/librustdoc/passes/html_tags.rs
+++ b/src/librustdoc/passes/html_tags.rs
@@ -46,9 +46,7 @@ fn drop_tag(
     f: &impl Fn(&str, &Range<usize>),
 ) {
     let tag_name_low = tag_name.to_lowercase();
-    if let Some(pos) = tags.iter().rev().position(|(t, _)| t.to_lowercase() == tag_name_low) {
-        // Because this is from a `rev` iterator, the position is reversed as well!
-        let pos = tags.len() - 1 - pos;
+    if let Some(pos) = tags.iter().rposition(|(t, _)| t.to_lowercase() == tag_name_low) {
         // If the tag is nested inside a "<script>" or a "<style>" tag, no warning should
         // be emitted.
         let should_not_warn = tags.iter().take(pos + 1).any(|(at, _)| {
@@ -83,9 +81,9 @@ fn extract_tag(
     range: Range<usize>,
     f: &impl Fn(&str, &Range<usize>),
 ) {
-    let mut iter = text.chars().enumerate().peekable();
+    let mut iter = text.char_indices().peekable();
 
-    'top: while let Some((start_pos, c)) = iter.next() {
+    while let Some((start_pos, c)) = iter.next() {
         if c == '<' {
             let mut tag_name = String::new();
             let mut is_closing = false;
@@ -118,20 +116,11 @@ fn extract_tag(
                             tags.push((tag_name, r));
                         }
                     }
-                    continue 'top;
-                }
-                // Some chars like 💩 are longer than 1 character, so we need to skip the other
-                // bytes as well to prevent stopping "in the middle" of a char.
-                for _ in 0..c.len_utf8() {
-                    iter.next();
+                    break;
                 }
+                iter.next();
             }
         }
-        // Some chars like 💩 are longer than 1 character, so we need to skip the other
-        // bytes as well to prevent stopping "in the middle" of a char.
-        for _ in 0..c.len_utf8() - 1 {
-            iter.next();
-        }
     }
 }
 
diff --git a/src/test/rustdoc-ui/intra-link-errors.rs b/src/test/rustdoc-ui/intra-link-errors.rs
index 8904828b047..0278caf3087 100644
--- a/src/test/rustdoc-ui/intra-link-errors.rs
+++ b/src/test/rustdoc-ui/intra-link-errors.rs
@@ -1,4 +1,3 @@
-#![allow(invalid_html_tags)]
 #![deny(broken_intra_doc_links)]
 //~^ NOTE lint level is defined
 
diff --git a/src/test/rustdoc-ui/intra-link-errors.stderr b/src/test/rustdoc-ui/intra-link-errors.stderr
index 798ae0bf011..b63f799535a 100644
--- a/src/test/rustdoc-ui/intra-link-errors.stderr
+++ b/src/test/rustdoc-ui/intra-link-errors.stderr
@@ -1,95 +1,95 @@
 error: unresolved link to `path::to::nonexistent::module`
-  --> $DIR/intra-link-errors.rs:8:6
+  --> $DIR/intra-link-errors.rs:7:6
    |
 LL | /// [path::to::nonexistent::module]
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the module `intra_link_errors` contains no item named `path`
    |
 note: the lint level is defined here
-  --> $DIR/intra-link-errors.rs:2:9
+  --> $DIR/intra-link-errors.rs:1:9
    |
 LL | #![deny(broken_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: unresolved link to `path::to::nonexistent::macro`
-  --> $DIR/intra-link-errors.rs:12:6
+  --> $DIR/intra-link-errors.rs:11:6
    |
 LL | /// [path::to::nonexistent::macro!]
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the module `intra_link_errors` contains no item named `path`
 
 error: unresolved link to `path::to::nonexistent::type`
-  --> $DIR/intra-link-errors.rs:16:6
+  --> $DIR/intra-link-errors.rs:15:6
    |
 LL | /// [type@path::to::nonexistent::type]
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the module `intra_link_errors` contains no item named `path`
 
 error: unresolved link to `std::io::not::here`
-  --> $DIR/intra-link-errors.rs:20:6
+  --> $DIR/intra-link-errors.rs:19:6
    |
 LL | /// [std::io::not::here]
    |      ^^^^^^^^^^^^^^^^^^ the module `io` contains no item named `not`
 
 error: unresolved link to `std::io::not::here`
-  --> $DIR/intra-link-errors.rs:24:6
+  --> $DIR/intra-link-errors.rs:23:6
    |
 LL | /// [type@std::io::not::here]
    |      ^^^^^^^^^^^^^^^^^^^^^^^ the module `io` contains no item named `not`
 
 error: unresolved link to `std::io::Error::x`
-  --> $DIR/intra-link-errors.rs:28:6
+  --> $DIR/intra-link-errors.rs:27:6
    |
 LL | /// [std::io::Error::x]
    |      ^^^^^^^^^^^^^^^^^ the struct `Error` has no field or associated item named `x`
 
 error: unresolved link to `std::io::ErrorKind::x`
-  --> $DIR/intra-link-errors.rs:32:6
+  --> $DIR/intra-link-errors.rs:31:6
    |
 LL | /// [std::io::ErrorKind::x]
    |      ^^^^^^^^^^^^^^^^^^^^^ the enum `ErrorKind` has no variant or associated item named `x`
 
 error: unresolved link to `f::A`
-  --> $DIR/intra-link-errors.rs:36:6
+  --> $DIR/intra-link-errors.rs:35:6
    |
 LL | /// [f::A]
    |      ^^^^ `f` is a function, not a module or type, and cannot have associated items
 
 error: unresolved link to `f::A`
-  --> $DIR/intra-link-errors.rs:40:6
+  --> $DIR/intra-link-errors.rs:39:6
    |
 LL | /// [f::A!]
    |      ^^^^^ `f` is a function, not a module or type, and cannot have associated items
 
 error: unresolved link to `S::A`
-  --> $DIR/intra-link-errors.rs:44:6
+  --> $DIR/intra-link-errors.rs:43:6
    |
 LL | /// [S::A]
    |      ^^^^ the struct `S` has no field or associated item named `A`
 
 error: unresolved link to `S::fmt`
-  --> $DIR/intra-link-errors.rs:48:6
+  --> $DIR/intra-link-errors.rs:47:6
    |
 LL | /// [S::fmt]
    |      ^^^^^^ the struct `S` has no field or associated item named `fmt`
 
 error: unresolved link to `E::D`
-  --> $DIR/intra-link-errors.rs:52:6
+  --> $DIR/intra-link-errors.rs:51:6
    |
 LL | /// [E::D]
    |      ^^^^ the enum `E` has no variant or associated item named `D`
 
 error: unresolved link to `u8::not_found`
-  --> $DIR/intra-link-errors.rs:56:6
+  --> $DIR/intra-link-errors.rs:55:6
    |
 LL | /// [u8::not_found]
    |      ^^^^^^^^^^^^^ the builtin type `u8` has no associated item named `not_found`
 
 error: unresolved link to `std::primitive::u8::not_found`
-  --> $DIR/intra-link-errors.rs:60:6
+  --> $DIR/intra-link-errors.rs:59:6
    |
 LL | /// [std::primitive::u8::not_found]
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the builtin type `u8` has no associated item named `not_found`
 
 error: unresolved link to `Vec::into_iter`
-  --> $DIR/intra-link-errors.rs:64:6
+  --> $DIR/intra-link-errors.rs:63:6
    |
 LL | /// [type@Vec::into_iter]
    |      ^^^^^^^^^^^^^^^^^^^
@@ -98,7 +98,7 @@ LL | /// [type@Vec::into_iter]
    |      help: to link to the associated function, add parentheses: `Vec::into_iter()`
 
 error: unresolved link to `S`
-  --> $DIR/intra-link-errors.rs:69:6
+  --> $DIR/intra-link-errors.rs:68:6
    |
 LL | /// [S!]
    |      ^^
@@ -107,7 +107,7 @@ LL | /// [S!]
    |      help: to link to the struct, prefix with `struct@`: `struct@S`
 
 error: unresolved link to `T::g`
-  --> $DIR/intra-link-errors.rs:87:6
+  --> $DIR/intra-link-errors.rs:86:6
    |
 LL | /// [type@T::g]
    |      ^^^^^^^^^
@@ -116,13 +116,13 @@ LL | /// [type@T::g]
    |      help: to link to the associated function, add parentheses: `T::g()`
 
 error: unresolved link to `T::h`
-  --> $DIR/intra-link-errors.rs:92:6
+  --> $DIR/intra-link-errors.rs:91:6
    |
 LL | /// [T::h!]
    |      ^^^^^ the trait `T` has no macro named `h`
 
 error: unresolved link to `S::h`
-  --> $DIR/intra-link-errors.rs:79:6
+  --> $DIR/intra-link-errors.rs:78:6
    |
 LL | /// [type@S::h]
    |      ^^^^^^^^^
@@ -131,7 +131,7 @@ LL | /// [type@S::h]
    |      help: to link to the associated function, add parentheses: `S::h()`
 
 error: unresolved link to `m`
-  --> $DIR/intra-link-errors.rs:99:6
+  --> $DIR/intra-link-errors.rs:98:6
    |
 LL | /// [m()]
    |      ^^^
diff --git a/src/test/rustdoc-ui/invalid-html-tags.rs b/src/test/rustdoc-ui/invalid-html-tags.rs
index a318b8ceca2..db97ab4456c 100644
--- a/src/test/rustdoc-ui/invalid-html-tags.rs
+++ b/src/test/rustdoc-ui/invalid-html-tags.rs
@@ -2,6 +2,7 @@
 
 //! <p>💩<p>
 //~^ ERROR unclosed HTML tag `p`
+//~^^ ERROR unclosed HTML tag `p`
 
 /// <img><input>
 /// <script>
diff --git a/src/test/rustdoc-ui/invalid-html-tags.stderr b/src/test/rustdoc-ui/invalid-html-tags.stderr
index 70d577bbfa9..caa5dd124c1 100644
--- a/src/test/rustdoc-ui/invalid-html-tags.stderr
+++ b/src/test/rustdoc-ui/invalid-html-tags.stderr
@@ -10,59 +10,65 @@ note: the lint level is defined here
 LL | #![deny(invalid_html_tags)]
    |         ^^^^^^^^^^^^^^^^^
 
+error: unclosed HTML tag `p`
+  --> $DIR/invalid-html-tags.rs:3:9
+   |
+LL | //! <p>💩<p>
+   |          ^^^
+
 error: unclosed HTML tag `unknown`
-  --> $DIR/invalid-html-tags.rs:10:5
+  --> $DIR/invalid-html-tags.rs:11:5
    |
 LL | /// <unknown>
    |     ^^^^^^^^^
 
 error: unclosed HTML tag `script`
-  --> $DIR/invalid-html-tags.rs:13:5
+  --> $DIR/invalid-html-tags.rs:14:5
    |
 LL | /// <script>
    |     ^^^^^^^^
 
 error: unclosed HTML tag `h2`
-  --> $DIR/invalid-html-tags.rs:18:7
+  --> $DIR/invalid-html-tags.rs:19:7
    |
 LL | ///   <h2>
    |       ^^^^
 
 error: unclosed HTML tag `h3`
-  --> $DIR/invalid-html-tags.rs:20:9
+  --> $DIR/invalid-html-tags.rs:21:9
    |
 LL | ///     <h3>
    |         ^^^^
 
 error: unopened HTML tag `hello`
-  --> $DIR/invalid-html-tags.rs:23:5
+  --> $DIR/invalid-html-tags.rs:24:5
    |
 LL | /// </hello>
    |     ^^^^^^^^
 
 error: unclosed HTML tag `p`
-  --> $DIR/invalid-html-tags.rs:28:14
+  --> $DIR/invalid-html-tags.rs:29:14
    |
 LL | ///    <br/> <p>
    |              ^^^
 
 error: unclosed HTML tag `div`
-  --> $DIR/invalid-html-tags.rs:40:5
+  --> $DIR/invalid-html-tags.rs:41:5
    |
 LL | /// <div style="hello">
    |     ^^^^
 
 error: unclosed HTML tag `h3`
-  --> $DIR/invalid-html-tags.rs:42:7
+  --> $DIR/invalid-html-tags.rs:43:7
    |
 LL | ///   <h3>
    |       ^^^^
 
 error: unclosed HTML tag `script`
-  --> $DIR/invalid-html-tags.rs:44:5
+  --> $DIR/invalid-html-tags.rs:45:5
    |
 LL | /// <script
    |     ^^^^^^
 
-error: aborting due to 10 previous errors
+error: aborting due to 11 previous errors
 
-- 
2.44.0