coerce_to_ref: no structural identity reliance

BoxyUwU · BoxyUwU · commit fe272c4d7306 · 2025-10-30T11:25:57.000Z
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -414,7 +414,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             }
         };
 
-        if coerced_a == a && mt_a.mutbl.is_not() && autoderef.step_count() == 1 {
+        if mt_a.mutbl.is_not() && mutbl_b.is_not() && autoderef.step_count() == 1 {
             // As a special case, if we would produce `&'a *x`, that's
             // a total no-op. We end up with the type `&'a T` just as
             // we started with. In that case, just skip it

Original file line number	Diff line number	Diff line change
`@@ -414,7 +414,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {`
`414`	`414`	`}`
`415`	`415`	`};`
`416`	`416`
`417`		`- if coerced_a == a && mt_a.mutbl.is_not() && autoderef.step_count() == 1 {`
	`417`	`+ if mt_a.mutbl.is_not() && mutbl_b.is_not() && autoderef.step_count() == 1 {`
`418`	`418`	// As a special case, if we would produce `&'a *x`, that's
`419`	`419`	// a total no-op. We end up with the type `&'a T` just as
`420`	`420`	`// we started with. In that case, just skip it`