Oct 28, 2025 · Oct 28, 2025 · Oct 27, 2025 · Oct 28, 2025
diff --git a/src/renderer/margin.rs b/src/renderer/margin.rs

        if self.computed_right - self.computed_left > self.term_width {
            // Trimming only whitespace isn't enough, let's get craftier.
            if self.label_right - self.whitespace_left <= self.term_width {
            if self.label_right.saturating_sub(self.whitespace_left) <= self.term_width
                // Trimming whitespace when the right-most label is somewhrere
                // within it would result in the label pointing to the wrong
                // place
                && self.label_right >= self.whitespace_left
            {
                // Attempt to fit the code window only trimming whitespace.
                self.computed_left = self.whitespace_left;
                self.computed_right = self.computed_left + self.term_width;
diff --git a/src/renderer/render.rs b/src/renderer/render.rs
    // Get the left-side margin to remove it
    let mut whitespace_margin = usize::MAX;
    for line_info in annotated_lines {
        // Whitespace can only be removed (aka considered leading)
        // if the lexer considers it whitespace.
        // non-rustc_lexer::is_whitespace() chars are reported as an
        // error (ex. no-break-spaces \u{a0}), and thus can't be considered
        // for removal during error reporting.
        let leading_whitespace = line_info
            .line
            .chars()
diff --git a/tests/rustc_tests.rs b/tests/rustc_tests.rs
    let renderer = renderer.decor_style(DecorStyle::Unicode);
    assert_data_eq!(renderer.render(input), expected_unicode);
 }

 #[test]
 fn emitter_overflow_bad_whitespace() {
    // tests/ui/errors/emitter-overflow-bad-whitespace.rs
    let source = r#"                                         fn main() {              return;              }
 "#;
    let title_0 = "Unicode character ' ' (No-Break Space) looks like ' ' (Space), but it is not";

    let report = &[
        Group::with_title(Level::ERROR.primary_title("unknown start of token: \u{a0}")).element(
            Snippet::source(source)
                .path("$DIR/emitter-overflow-bad-whitespace.rs")
                .line_start(10)
                .annotation(AnnotationKind::Primary.span(0..2)),
        ),
        Group::with_title(Level::HELP.secondary_title(title_0)).element(
            Snippet::source(source)
                .path("$DIR/emitter-overflow-bad-whitespace.rs")
                .line_start(10)
                .patch(Patch::new(0..2, " ")),
        ),
    ];
    let expected_ascii = str![[r#"
 error: unknown start of token:  
  --> $DIR/emitter-overflow-bad-whitespace.rs:10:1
   |
 10 |     ...
   | ^
   |
 help: Unicode character ' ' (No-Break Space) looks like ' ' (Space), but it is not
   |
 10 |                                          fn main() {              return;              }
   | +
 "#]];
    let renderer_ascii = Renderer::plain().term_width(1);
    assert_data_eq!(renderer_ascii.render(report), expected_ascii);

    let expected_unicode = str![[r#"
 error: unknown start of token:  
   ╭▸ $DIR/emitter-overflow-bad-whitespace.rs:10:1
   │
 10 │       …
   │ ━
   ╰╴
 help: Unicode character ' ' (No-Break Space) looks like ' ' (Space), but it is not
   ╭╴
 10 │                                          fn main() {              return;              }
   ╰╴+
 "#]];
    let renderer_unicode = renderer_ascii.decor_style(DecorStyle::Unicode);
    assert_data_eq!(renderer_unicode.render(report), expected_unicode);
 }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -71,7 +71,12 @@ impl Margin {

		if self.computed_right - self.computed_left > self.term_width {
		// Trimming only whitespace isn't enough, let's get craftier.
		if self.label_right - self.whitespace_left <= self.term_width {
		if self.label_right.saturating_sub(self.whitespace_left) <= self.term_width
		// Trimming whitespace when the right-most label is somewhrere
		// within it would result in the label pointing to the wrong
		// place
		&& self.label_right >= self.whitespace_left
		{
		// Attempt to fit the code window only trimming whitespace.
		self.computed_left = self.whitespace_left;
		self.computed_right = self.computed_left + self.term_width;
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -622,11 +622,6 @@ fn render_snippet_annotations(
		// Get the left-side margin to remove it
		let mut whitespace_margin = usize::MAX;
		for line_info in annotated_lines {
		// Whitespace can only be removed (aka considered leading)
		// if the lexer considers it whitespace.
		// non-rustc_lexer::is_whitespace() chars are reported as an
		// error (ex. no-break-spaces \u{a0}), and thus can't be considered
		// for removal during error reporting.
		let leading_whitespace = line_info
		.line
		.chars()
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -5646,3 +5646,55 @@ LL │ static ROOK_ATTACKS_TABLE: () = {
		let renderer = renderer.decor_style(DecorStyle::Unicode);
		assert_data_eq!(renderer.render(input), expected_unicode);
		}

		#[test]
		fn emitter_overflow_bad_whitespace() {
		// tests/ui/errors/emitter-overflow-bad-whitespace.rs
		let source = r#" fn main() { return; }
		"#;
		let title_0 = "Unicode character ' ' (No-Break Space) looks like ' ' (Space), but it is not";

		let report = &[
		Group::with_title(Level::ERROR.primary_title("unknown start of token: \u{a0}")).element(
		Snippet::source(source)
		.path("$DIR/emitter-overflow-bad-whitespace.rs")
		.line_start(10)
		.annotation(AnnotationKind::Primary.span(0..2)),
		),
		Group::with_title(Level::HELP.secondary_title(title_0)).element(
		Snippet::source(source)
		.path("$DIR/emitter-overflow-bad-whitespace.rs")
		.line_start(10)
		.patch(Patch::new(0..2, " ")),
		),
		];
		let expected_ascii = str![[r#"
		error: unknown start of token:
		--> $DIR/emitter-overflow-bad-whitespace.rs:10:1
		\|
		10 \| ...
		\| ^
		\|
		help: Unicode character ' ' (No-Break Space) looks like ' ' (Space), but it is not
		\|
		10 \| fn main() { return; }
		\| +
		"#]];
		let renderer_ascii = Renderer::plain().term_width(1);
		assert_data_eq!(renderer_ascii.render(report), expected_ascii);

		let expected_unicode = str![[r#"
		error: unknown start of token:
		╭▸ $DIR/emitter-overflow-bad-whitespace.rs:10:1
		│
		10 │ …
		│ ━
		╰╴
		help: Unicode character ' ' (No-Break Space) looks like ' ' (Space), but it is not
		╭╴
		10 │ fn main() { return; }
		╰╴+
		"#]];
		let renderer_unicode = renderer_ascii.decor_style(DecorStyle::Unicode);
		assert_data_eq!(renderer_unicode.render(report), expected_unicode);
		}