From 2d2307e6163816511790c3bb61e07913d9cb66c1 Mon Sep 17 00:00:00 2001
From: Lieselotte <52315535+she3py@users.noreply.github.com>
Date: Thu, 13 Mar 2025 13:01:53 +0100
Subject: [PATCH] Dedup `&mut *` reborrow suggestion in loops

---
 .../src/diagnostics/conflict_errors.rs              | 13 -------------
 tests/ui/borrowck/mut-borrow-in-loop-2.stderr       |  4 ----
 2 files changed, 17 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 2694a1eda78d7..a2df4e4e47d5c 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -181,7 +181,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             let closure = self.add_moved_or_invoked_closure_note(location, used_place, &mut err);
 
             let mut is_loop_move = false;
-            let mut in_pattern = false;
             let mut seen_spans = FxIndexSet::default();
 
             for move_site in &move_site_vec {
@@ -204,7 +203,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     self.suggest_ref_or_clone(
                         mpi,
                         &mut err,
-                        &mut in_pattern,
                         move_spans,
                         moved_place.as_ref(),
                         &mut has_suggest_reborrow,
@@ -256,15 +254,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             let place = &self.move_data.move_paths[mpi].place;
             let ty = place.ty(self.body, self.infcx.tcx).ty;
 
-            // If we're in pattern, we do nothing in favor of the previous suggestion (#80913).
-            // Same for if we're in a loop, see #101119.
-            if is_loop_move & !in_pattern && !matches!(use_spans, UseSpans::ClosureUse { .. }) {
-                if let ty::Ref(_, _, hir::Mutability::Mut) = ty.kind() {
-                    // We have a `&mut` ref, we need to reborrow on each iteration (#62112).
-                    self.suggest_reborrow(&mut err, span, moved_place);
-                }
-            }
-
             if self.infcx.param_env.caller_bounds().iter().any(|c| {
                 c.as_trait_clause().is_some_and(|pred| {
                     pred.skip_binder().self_ty() == ty && self.infcx.tcx.is_fn_trait(pred.def_id())
@@ -330,7 +319,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         &self,
         mpi: MovePathIndex,
         err: &mut Diag<'infcx>,
-        in_pattern: &mut bool,
         move_spans: UseSpans<'tcx>,
         moved_place: PlaceRef<'tcx>,
         has_suggest_reborrow: &mut bool,
@@ -545,7 +533,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 && !move_span.is_dummy()
                 && !self.infcx.tcx.sess.source_map().is_imported(move_span)
             {
-                *in_pattern = true;
                 let mut sugg = vec![(pat.span.shrink_to_lo(), "ref ".to_string())];
                 if let Some(pat) = finder.parent_pat {
                     sugg.insert(0, (pat.span.shrink_to_lo(), "ref ".to_string()));
diff --git a/tests/ui/borrowck/mut-borrow-in-loop-2.stderr b/tests/ui/borrowck/mut-borrow-in-loop-2.stderr
index 4f32df1eb24e2..46e06bc91b91c 100644
--- a/tests/ui/borrowck/mut-borrow-in-loop-2.stderr
+++ b/tests/ui/borrowck/mut-borrow-in-loop-2.stderr
@@ -12,10 +12,6 @@ help: consider creating a fresh reborrow of `value` here
    |
 LL |         Other::handle(&mut *value);
    |                       ++++++
-help: consider creating a fresh reborrow of `value` here
-   |
-LL |         Other::handle(&mut *value);
-   |                       ++++++
 
 error: aborting due to 1 previous error