3 files changed, 6 insertions, 8 deletions
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 4352de3ad25..05b9cbfbc06 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -11,8 +11,7 @@ use rustc_error_messages::{FluentValue, fluent_value_from_str_list_sep_by_and};
 use rustc_lint_defs::Applicability;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::Symbol;
-use rustc_span::{DUMMY_SP, Span};
+use rustc_span::{DUMMY_SP, Span, Symbol};
 use tracing::debug;
 
 use crate::snippet::Style;
diff --git a/compiler/rustc_errors/src/diagnostic_impls.rs b/compiler/rustc_errors/src/diagnostic_impls.rs
index b4510371323..d179396398f 100644
--- a/compiler/rustc_errors/src/diagnostic_impls.rs
+++ b/compiler/rustc_errors/src/diagnostic_impls.rs
@@ -9,9 +9,8 @@ use rustc_abi::TargetDataLayoutErrors;
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_ast_pretty::pprust;
 use rustc_macros::Subdiagnostic;
-use rustc_span::Span;
 use rustc_span::edition::Edition;
-use rustc_span::symbol::{Ident, MacroRulesNormalizedIdent, Symbol};
+use rustc_span::{Ident, MacroRulesNormalizedIdent, Span, Symbol};
 use rustc_target::spec::{PanicStrategy, SplitDebuginfo, StackProtector, TargetTuple};
 use rustc_type_ir::{ClosureKind, FloatTy};
 use {rustc_ast as ast, rustc_hir as hir};
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 25d41462556..58fe3ec4b85 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -1569,18 +1569,18 @@ impl DiagCtxtInner {
                 debug!(?diagnostic);
                 debug!(?self.emitted_diagnostics);
 
-                let already_emitted_sub = |sub: &mut Subdiag| {
+                let not_yet_emitted = |sub: &mut Subdiag| {
                     debug!(?sub);
                     if sub.level != OnceNote && sub.level != OnceHelp {
-                        return false;
+                        return true;
                     }
                     let mut hasher = StableHasher::new();
                     sub.hash(&mut hasher);
                     let diagnostic_hash = hasher.finish();
                     debug!(?diagnostic_hash);
-                    !self.emitted_diagnostics.insert(diagnostic_hash)
+                    self.emitted_diagnostics.insert(diagnostic_hash)
                 };
-                diagnostic.children.extract_if(already_emitted_sub).for_each(|_| {});
+                diagnostic.children.retain_mut(not_yet_emitted);
                 if already_emitted {
                     let msg = "duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`";
                     diagnostic.sub(Note, msg, MultiSpan::new());