Auto merge of #124890 - matthiaskrgr:rollup-25iq88h, r=matthiaskrgr

Rollup of 3 pull requests

Successful merges:

 - #124548 (Handle normalization failure in `struct_tail_erasing_lifetimes`)
 - #124761 (Fix insufficient logic when searching for the underlying allocation)
 - #124864 (rustdoc: use stability, instead of features, to decide what to show)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 7 insertions, 0 deletions

diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs
index 9fed91f7262..63d55a73a98 100644
--- a/compiler/rustc_lint/src/reference_casting.rs
+++ b/compiler/rustc_lint/src/reference_casting.rs
@@ -199,6 +199,13 @@ fn is_cast_to_bigger_memory_layout<'tcx>(
     let e_alloc = cx.expr_or_init(e);
     let e_alloc =
         if let ExprKind::AddrOf(_, _, inner_expr) = e_alloc.kind { inner_expr } else { e_alloc };
+
+    // if the current expr looks like this `&mut expr[index]` then just looking
+    // at `expr[index]` won't give us the underlying allocation, so we just skip it
+    if let ExprKind::Index(..) = e_alloc.kind {
+        return None;
+    }
+
     let alloc_ty = cx.typeck_results().node_type(e_alloc.hir_id);
 
     // if we do not find it we bail out, as this may not be UB