From 5aedef17f975e64c4a012d22af2e151e759d9196 Mon Sep 17 00:00:00 2001
From: Scott Schafer <schaferjscott@gmail.com>
Date: Mon, 28 Jul 2025 20:04:48 -0600
Subject: [PATCH] chore: Remove unneeded ansi escape resets from output

---
 compiler/rustc_errors/src/emitter.rs          |  3 +-
 compiler/rustc_errors/src/markdown/term.rs    | 72 +++++++++++--------
 .../src/markdown/tests/output.stdout          | 46 ++++++------
 tests/ui/lint/use_suggestion_json.stderr      | 38 +++++-----
 4 files changed, 86 insertions(+), 73 deletions(-)

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 33b5ffdeb62f..66a0bfd777a2 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -3408,7 +3408,6 @@ pub(crate) fn emit_to_destination(
     short_message: bool,
 ) -> io::Result<()> {
     use crate::lock;
-    const RESET: anstyle::Reset = anstyle::Reset;
 
     // In order to prevent error message interleaving, where multiple error lines get intermixed
     // when multiple compiler processes error simultaneously, we emit errors with additional
@@ -3426,7 +3425,7 @@ pub(crate) fn emit_to_destination(
     for (pos, line) in rendered_buffer.iter().enumerate() {
         for part in line {
             let style = part.style.anstyle(*lvl);
-            write!(dst, "{RESET}{style}{}{RESET}", part.text)?;
+            write!(dst, "{style}{}{style:#}", part.text)?;
         }
         if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
             writeln!(dst)?;
diff --git a/compiler/rustc_errors/src/markdown/term.rs b/compiler/rustc_errors/src/markdown/term.rs
index 4c5dc86e3859..b0ce01548f00 100644
--- a/compiler/rustc_errors/src/markdown/term.rs
+++ b/compiler/rustc_errors/src/markdown/term.rs
@@ -6,7 +6,6 @@
 use crate::markdown::{MdStream, MdTree};
 
 const DEFAULT_COLUMN_WIDTH: usize = 140;
-const RESET: anstyle::Reset = anstyle::Reset;
 
 thread_local! {
     /// Track the position of viewable characters in our buffer
@@ -31,53 +30,52 @@ fn write_stream(
     default: Option<Style>,
     indent: usize,
 ) -> io::Result<()> {
-    match default {
-        Some(c) => write!(buf, "{c:#}{c}")?,
-        None => write!(buf, "{RESET}")?,
-    }
-
     for tt in stream {
         write_tt(tt, buf, default, indent)?;
-        if let Some(c) = default {
-            write!(buf, "{c:#}{c}")?;
-        }
     }
+    reset_opt_style(buf, default)?;
 
-    write!(buf, "{RESET}")?;
     Ok(())
 }
 
 fn write_tt(
     tt: &MdTree<'_>,
     buf: &mut Vec<u8>,
-    _default: Option<Style>,
+    default: Option<Style>,
     indent: usize,
 ) -> io::Result<()> {
     match tt {
         MdTree::CodeBlock { txt, lang: _ } => {
-            write!(buf, "{RESET}")?;
+            reset_opt_style(buf, default)?;
             let style = Style::new().effects(Effects::DIMMED);
-            write!(buf, "{style}{txt}")?;
+            write!(buf, "{style}{txt}{style:#}")?;
+            render_opt_style(buf, default)?;
         }
         MdTree::CodeInline(txt) => {
-            write!(buf, "{RESET}")?;
-            let style = Style::new().effects(Effects::DIMMED);
-            write_wrapping(buf, txt, indent, None, Some(style))?;
+            reset_opt_style(buf, default)?;
+            write_wrapping(buf, txt, indent, None, Some(Style::new().effects(Effects::DIMMED)))?;
+            render_opt_style(buf, default)?;
         }
         MdTree::Strong(txt) => {
-            write!(buf, "{RESET}")?;
-            let style = Style::new().effects(Effects::BOLD);
-            write_wrapping(buf, txt, indent, None, Some(style))?;
+            reset_opt_style(buf, default)?;
+            write_wrapping(buf, txt, indent, None, Some(Style::new().effects(Effects::BOLD)))?;
+            render_opt_style(buf, default)?;
         }
         MdTree::Emphasis(txt) => {
-            write!(buf, "{RESET}")?;
-            let style = Style::new().effects(Effects::ITALIC);
-            write_wrapping(buf, txt, indent, None, Some(style))?;
+            reset_opt_style(buf, default)?;
+            write_wrapping(buf, txt, indent, None, Some(Style::new().effects(Effects::ITALIC)))?;
+            render_opt_style(buf, default)?;
         }
         MdTree::Strikethrough(txt) => {
-            write!(buf, "{RESET}")?;
-            let style = Style::new().effects(Effects::STRIKETHROUGH);
-            write_wrapping(buf, txt, indent, None, Some(style))?;
+            reset_opt_style(buf, default)?;
+            write_wrapping(
+                buf,
+                txt,
+                indent,
+                None,
+                Some(Style::new().effects(Effects::STRIKETHROUGH)),
+            )?;
+            render_opt_style(buf, default)?;
         }
         MdTree::PlainText(txt) => {
             write_wrapping(buf, txt, indent, None, None)?;
@@ -105,7 +103,11 @@ fn write_tt(
                 4.. => AnsiColor::Cyan.on_default().effects(Effects::UNDERLINE | Effects::ITALIC),
                 0 => unreachable!(),
             };
+            reset_opt_style(buf, default)?;
+            write!(buf, "{cs}")?;
             write_stream(stream, buf, Some(cs), 0)?;
+            write!(buf, "{cs:#}")?;
+            render_opt_style(buf, default)?;
             buf.write_all(b"\n")?;
         }
         MdTree::OrderedListItem(n, stream) => {
@@ -122,8 +124,20 @@ fn write_tt(
         MdTree::Comment(_) | MdTree::LinkDef { .. } | MdTree::RefLink { .. } => unreachable!(),
     }
 
-    write!(buf, "{RESET}")?;
+    Ok(())
+}
 
+fn render_opt_style(buf: &mut Vec<u8>, style: Option<Style>) -> io::Result<()> {
+    if let Some(style) = &style {
+        write!(buf, "{style}")?;
+    }
+    Ok(())
+}
+
+fn reset_opt_style(buf: &mut Vec<u8>, style: Option<Style>) -> io::Result<()> {
+    if let Some(style) = &style {
+        write!(buf, "{style:#}")?;
+    }
     Ok(())
 }
 
@@ -141,9 +155,8 @@ fn write_wrapping(
     link_url: Option<&str>,
     style: Option<Style>,
 ) -> io::Result<()> {
-    if let Some(style) = &style {
-        write!(buf, "{style}")?;
-    }
+    render_opt_style(buf, style)?;
+
     let ind_ws = &b"          "[..indent];
     let mut to_write = text;
     if let Some(url) = link_url {
@@ -191,6 +204,7 @@ fn write_wrapping(
         if link_url.is_some() {
             buf.write_all(b"\x1b]8;;\x1b\\")?;
         }
+        reset_opt_style(buf, style)?;
         Ok(())
     })
 }
diff --git a/compiler/rustc_errors/src/markdown/tests/output.stdout b/compiler/rustc_errors/src/markdown/tests/output.stdout
index 865ac175daf1..df46bc5e854f 100644
--- a/compiler/rustc_errors/src/markdown/tests/output.stdout
+++ b/compiler/rustc_errors/src/markdown/tests/output.stdout
@@ -1,35 +1,35 @@
-H1 Heading ]8;;http://docs.rs\with a link]8;;\
-H1 content: some words in bold and so does inline code
+H1 Heading ]8;;http://docs.rs\with a link]8;;\
+H1 content: some words in bold and so does inline code
 
-H2 Heading
-H2 content: some words in italic
+H2 Heading
+H2 content: some words in italic
 
-H3 Heading
-H3 content: strikethrough text
+H3 Heading
+H3 content: strikethrough text
 
-H4 Heading
-H4 content: A ]8;;https://docs.rs\simple link]8;;\ and a ]8;;http://docs.rs\remote-link]8;;\.
---------------------------------------------------------------------------------------------------------------------------------------------
-A section break was above. We can also do paragraph breaks:
+H4 Heading
+H4 content: A ]8;;https://docs.rs\simple link]8;;\ and a ]8;;http://docs.rs\remote-link]8;;\.
+--------------------------------------------------------------------------------------------------------------------------------------------
+A section break was above. We can also do paragraph breaks:
 
-(new paragraph) and unordered lists:
+(new paragraph) and unordered lists:
 
-*   Item 1 in code
-*   Item 2 in italics
+*   Item 1 in code
+*   Item 2 in italics
 
-Or ordered:
+Or ordered:
 
-1.  Item 1 in bold
-2.  Item 2 with some long lines that should wrap: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean ac mattis nunc. Phasellus
-    elit quam, pulvinar ac risus in, dictum vehicula turpis. Vestibulum neque est, accumsan in cursus sit amet, dictum a nunc. Suspendisse
-    aliquet, lorem eu eleifend accumsan, magna neque sodales nisi, a aliquet lectus leo eu sem.
---------------------------------------------------------------------------------------------------------------------------------------------
-Code
-Both inline code and code blocks are supported:
+1.  Item 1 in bold
+2.  Item 2 with some long lines that should wrap: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean ac mattis nunc. Phasellus
+    elit quam, pulvinar ac risus in, dictum vehicula turpis. Vestibulum neque est, accumsan in cursus sit amet, dictum a nunc. Suspendisse
+    aliquet, lorem eu eleifend accumsan, magna neque sodales nisi, a aliquet lectus leo eu sem.
+--------------------------------------------------------------------------------------------------------------------------------------------
+Code
+Both inline code and code blocks are supported:
 
-/// A rust enum
+/// A rust enum
 #[derive(Debug, PartialEq, Clone)]
 enum Foo {
     /// Start of line
     Bar
-}
+}
diff --git a/tests/ui/lint/use_suggestion_json.stderr b/tests/ui/lint/use_suggestion_json.stderr
index 86ee6746ef41..4dc414b7a65d 100644
--- a/tests/ui/lint/use_suggestion_json.stderr
+++ b/tests/ui/lint/use_suggestion_json.stderr
@@ -403,23 +403,23 @@ mod foo {
       "rendered": null
     }
   ],
-  "rendered": "\u001b[0m\u001b[1m\u001b[91merror[E0412]\u001b[0m\u001b[0m\u001b[1m: cannot find type `Iter` in this scope\u001b[0m
-\u001b[0m  \u001b[0m\u001b[0m\u001b[1m\u001b[94m--> \u001b[0m\u001b[0m$DIR/use_suggestion_json.rs:12:12\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m\u001b[1m\u001b[94mLL\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m\u001b[0m \u001b[0m\u001b[0m    let x: Iter;\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m\u001b[0m            \u001b[0m\u001b[0m\u001b[1m\u001b[91m^^^^\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[1m\u001b[91mnot found in this scope\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m\u001b[1m\u001b[96mhelp\u001b[0m\u001b[0m: consider importing one of these structs\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m\u001b[1m\u001b[94mLL\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[92m+ use std::collections::binary_heap::Iter;\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m\u001b[1m\u001b[94mLL\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[92m+ use std::collections::btree_map::Iter;\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m\u001b[1m\u001b[94mLL\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[92m+ use std::collections::btree_set::Iter;\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m\u001b[1m\u001b[94mLL\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[92m+ use std::collections::hash_map::Iter;\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m|\u001b[0m
-\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[94m= \u001b[0m\u001b[0mand 9 other candidates\u001b[0m
+  "rendered": "\u001b[1m\u001b[91merror[E0412]\u001b[0m\u001b[1m: cannot find type `Iter` in this scope\u001b[0m
+  \u001b[1m\u001b[94m--> \u001b[0m$DIR/use_suggestion_json.rs:12:12
+   \u001b[1m\u001b[94m|\u001b[0m
+\u001b[1m\u001b[94mLL\u001b[0m \u001b[1m\u001b[94m|\u001b[0m     let x: Iter;
+   \u001b[1m\u001b[94m|\u001b[0m            \u001b[1m\u001b[91m^^^^\u001b[0m \u001b[1m\u001b[91mnot found in this scope\u001b[0m
+   \u001b[1m\u001b[94m|\u001b[0m
+\u001b[1m\u001b[96mhelp\u001b[0m: consider importing one of these structs
+   \u001b[1m\u001b[94m|\u001b[0m
+\u001b[1m\u001b[94mLL\u001b[0m \u001b[92m+ use std::collections::binary_heap::Iter;\u001b[0m
+   \u001b[1m\u001b[94m|\u001b[0m
+\u001b[1m\u001b[94mLL\u001b[0m \u001b[92m+ use std::collections::btree_map::Iter;\u001b[0m
+   \u001b[1m\u001b[94m|\u001b[0m
+\u001b[1m\u001b[94mLL\u001b[0m \u001b[92m+ use std::collections::btree_set::Iter;\u001b[0m
+   \u001b[1m\u001b[94m|\u001b[0m
+\u001b[1m\u001b[94mLL\u001b[0m \u001b[92m+ use std::collections::hash_map::Iter;\u001b[0m
+   \u001b[1m\u001b[94m|\u001b[0m
+   \u001b[1m\u001b[94m= \u001b[0mand 9 other candidates
 
 "
 }
@@ -430,7 +430,7 @@ mod foo {
   "level": "error",
   "spans": [],
   "children": [],
-  "rendered": "\u001b[0m\u001b[1m\u001b[91merror\u001b[0m\u001b[0m\u001b[1m: aborting due to 1 previous error\u001b[0m
+  "rendered": "\u001b[1m\u001b[91merror\u001b[0m\u001b[1m: aborting due to 1 previous error\u001b[0m
 
 "
 }
@@ -441,6 +441,6 @@ mod foo {
   "level": "failure-note",
   "spans": [],
   "children": [],
-  "rendered": "\u001b[0m\u001b[1mFor more information about this error, try `rustc --explain E0412`.\u001b[0m
+  "rendered": "\u001b[1mFor more information about this error, try `rustc --explain E0412`.\u001b[0m
 "
 }