Fix character split when strip code

src/formatter/mod.rs

@@ -1,6 +1,7 @@
 use std::{
  cmp,
  fmt::{self, Display, Write},
+ iter::once,
 };
 
 pub mod style;
@@ -217,16 +218,21 @@ impl<'a> DisplayList<'a> {
  } else {
  false
  };
+ let mut ended = false;
  let range = text
  .char_indices()
+ .chain(once((text.len(), '\0')))
  .skip(left)
  .take_while(|(_, ch)| {
+ if ended {
+ return false;
+ }
  // Make sure that the trimming on the right will fall within the terminal width.
  // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
  // For now, just accept that sometimes the code line will be longer than desired.
  taken += unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
  if taken > right - left {
- return false;
+ ended = true;
  }
  true
  })
@@ -238,7 +244,7 @@ impl<'a> DisplayList<'a> {
  }
  });
 
- text[range.0.expect("One character at line")..=range.1].fmt(f)?;
+ text[range.0.expect("One character at line")..range.1].fmt(f)?;
 
  if cut_right {
  // We have stripped some code after the right-most span end, make it clear we did so.

tests/fixtures/no-color/strip_line_char.toml

@@ -0,0 +1,25 @@
+[title]
+id = "E0308"
+label = "mismatched types"
+annotation_type = "Error"
+
+[[slices]]
+source = " let _: () = 42ñ"
+line_start = 4
+origin = "$DIR/whitespace-trimming.rs"
+
+[[slices.annotations]]
+label = "expected (), found integer"
+annotation_type = "Error"
+range = [192, 194]
+
+[opt]
+color = false
+anonymized_line_numbers = true
+[opt.margin]
+whitespace_left = 180
+span_left = 192
+span_right = 194
+label_right = 221
+column_width = 140
+max_line_len = 195

tests/fixtures/no-color/strip_line_char.txt

@@ -0,0 +1,6 @@
+error[E0308]: mismatched types
+ --> $DIR/whitespace-trimming.rs:4:193
+ |
+LL | ... let _: () = 42ñ
+ | ^^ expected (), found integer
+ |