From c30d31e6cd168d0655f2445c2d8f222d954e61a6 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Apr 2024 16:23:25 -0500
Subject: [PATCH 1/2] test(parser): Show emoji bug

---
 crates/toml_edit/tests/testsuite/invalid.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/crates/toml_edit/tests/testsuite/invalid.rs b/crates/toml_edit/tests/testsuite/invalid.rs
index 5e7acca0..a156792e 100644
--- a/crates/toml_edit/tests/testsuite/invalid.rs
+++ b/crates/toml_edit/tests/testsuite/invalid.rs
@@ -209,3 +209,12 @@ dotted key `k1` attempted to extend non-table type (integer)
     let err = toml_input.parse::<toml_edit::DocumentMut>().unwrap_err();
     snapbox::assert_eq(expected_err, err.to_string());
 }
+
+#[test]
+#[should_panic]
+fn emoji_error_span() {
+    let input = "😀";
+    let err = input.parse::<toml_edit::DocumentMut>().unwrap_err();
+    dbg!(err.span());
+    let _ = &input[err.span().unwrap()];
+}

From 1a6ed6e0669e98f7c3875223d81fe17d833912f2 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Apr 2024 16:38:51 -0500
Subject: [PATCH 2/2] fix(parser): Return correct span for multi-byte
 characters

This is a step towards addressing rust-lang/cargo#13772
---
 crates/toml_edit/src/error.rs                  | 18 +++++++++++-------
 .../invalid/key/special-character.stderr       |  2 +-
 .../fixtures/invalid/table/no-close-2.stderr   |  2 +-
 crates/toml_edit/tests/testsuite/invalid.rs    |  4 ++--
 4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/crates/toml_edit/src/error.rs b/crates/toml_edit/src/error.rs
index d9630fca..6a278024 100644
--- a/crates/toml_edit/src/error.rs
+++ b/crates/toml_edit/src/error.rs
@@ -21,19 +21,23 @@ impl TomlError {
     ) -> Self {
         use winnow::stream::Stream;
 
+        let message = error.inner().to_string();
+        let raw = raw.finish();
+        let raw = String::from_utf8(raw.to_owned()).expect("original document was utf8");
+
         let offset = error.offset();
-        let span = if offset == raw.len() {
-            offset..offset
+        let mut indices = raw[offset..].char_indices();
+        indices.next();
+        let len = if let Some((index, _)) = indices.next() {
+            index
         } else {
-            offset..(offset + 1)
+            raw.len()
         };
-
-        let message = error.inner().to_string();
-        let raw = raw.finish();
+        let span = offset..(offset + len);
 
         Self {
             message,
-            raw: Some(String::from_utf8(raw.to_owned()).expect("original document was utf8")),
+            raw: Some(raw),
             keys: Vec::new(),
             span: Some(span),
         }
diff --git a/crates/toml_edit/tests/fixtures/invalid/key/special-character.stderr b/crates/toml_edit/tests/fixtures/invalid/key/special-character.stderr
index 7ada2f21..10592cfb 100644
--- a/crates/toml_edit/tests/fixtures/invalid/key/special-character.stderr
+++ b/crates/toml_edit/tests/fixtures/invalid/key/special-character.stderr
@@ -1,5 +1,5 @@
 TOML parse error at line 1, column 1
   |
 1 | μ = "greek small letter mu"
-  | ^
+  | ^^
 invalid key
diff --git a/crates/toml_edit/tests/fixtures/invalid/table/no-close-2.stderr b/crates/toml_edit/tests/fixtures/invalid/table/no-close-2.stderr
index a7adf382..26fc7875 100644
--- a/crates/toml_edit/tests/fixtures/invalid/table/no-close-2.stderr
+++ b/crates/toml_edit/tests/fixtures/invalid/table/no-close-2.stderr
@@ -1,6 +1,6 @@
 TOML parse error at line 1, column 25
   |
 1 | [closing-bracket.missingö
-  |                         ^
+  |                         ^^
 invalid table header
 expected `.`, `]`
diff --git a/crates/toml_edit/tests/testsuite/invalid.rs b/crates/toml_edit/tests/testsuite/invalid.rs
index a156792e..79724163 100644
--- a/crates/toml_edit/tests/testsuite/invalid.rs
+++ b/crates/toml_edit/tests/testsuite/invalid.rs
@@ -211,10 +211,10 @@ dotted key `k1` attempted to extend non-table type (integer)
 }
 
 #[test]
-#[should_panic]
 fn emoji_error_span() {
     let input = "😀";
     let err = input.parse::<toml_edit::DocumentMut>().unwrap_err();
     dbg!(err.span());
-    let _ = &input[err.span().unwrap()];
+    let actual = &input[err.span().unwrap()];
+    assert_eq!(actual, input);
 }