Remove strict invariant node_type on hir_type during ty privacy visit

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -2518,15 +2518,29 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     ) -> Const<'tcx> {
         let tcx = self.tcx();
 
+        let found_tuple = || {
+            tcx.sess
+                .source_map()
+                .span_to_snippet(span)
+                .map(|snippet| format!("`{snippet}`"))
+                .unwrap_or_else(|_| "const tuple".to_string())
+        };
+
         let tys = match ty.kind() {
             ty::Tuple(tys) => tys,
             ty::Error(e) => return Const::new_error(tcx, *e),
             _ => {
-                let e = tcx.dcx().span_err(span, format!("expected `{}`, found const tuple", ty));
+                let e =
+                    tcx.dcx().span_err(span, format!("expected `{}`, found {}", ty, found_tuple()));
                 return Const::new_error(tcx, e);
             }
         };
 
+        if exprs.len() != tys.len() {
+            let e = tcx.dcx().span_err(span, format!("expected `{}`, found {}", ty, found_tuple()));
+            return Const::new_error(tcx, e);
+        }
+
         let exprs = exprs
             .iter()
             .zip(tys.iter())

compiler/rustc_hir_typeck/src/writeback.rs

@@ -348,7 +348,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for WritebackCx<'cx, 'tcx> {
     fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx, AmbigArg>) {
         intravisit::walk_ty(self, hir_ty);
         // If there are type checking errors, Type privacy pass will stop,
-        // so we may not get the type from hid_id, see #104513
+        // so we may not get the type from hir_id, see #104513
         if let Some(ty) = self.fcx.node_ty_opt(hir_ty.hir_id) {
             let ty = self.resolve(ty, &hir_ty.span);
             self.write_ty_to_typeck_results(hir_ty.hir_id, ty);

tests/ui/const-generics/mgca/tuple_expr_arg_bad-issue-151048.rs

@@ -2,7 +2,7 @@
 #![expect(incomplete_features)]
 
 struct Y {
-    stuff: [u8; { ([1, 2], 3, [4, 5]) }], //~ ERROR expected `usize`, found const tuple
+    stuff: [u8; { ([1, 2], 3, [4, 5]) }], //~ ERROR expected `usize`, found `([1, 2], 3, [4, 5])`
 }
 
 fn main() {}

tests/ui/const-generics/mgca/tuple_expr_arg_bad-issue-151048.stderr

@@ -1,4 +1,4 @@
-error: expected `usize`, found const tuple
+error: expected `usize`, found `([1, 2], 3, [4, 5])`
   --> $DIR/tuple_expr_arg_bad-issue-151048.rs:5:19
    |
 LL |     stuff: [u8; { ([1, 2], 3, [4, 5]) }],

tests/ui/const-generics/mgca/tuple_expr_arg_mismatch_type.rs

@@ -2,7 +2,7 @@
 #![expect(incomplete_features)]
 
 pub fn takes_nested_tuple<const N: u32>() {
-    takes_nested_tuple::<{ () }> //~ ERROR expected `u32`, found const tuple
+    takes_nested_tuple::<{ () }> //~ ERROR expected `u32`, found `()`
 }
 
 fn main() {}

tests/ui/const-generics/mgca/tuple_expr_arg_mismatch_type.stderr

@@ -1,4 +1,4 @@
-error: expected `u32`, found const tuple
+error: expected `u32`, found `()`
   --> $DIR/tuple_expr_arg_mismatch_type.rs:5:28
    |
 LL |     takes_nested_tuple::<{ () }>

tests/ui/const-generics/mgca/tuple_expr_arg_unbounded_assoc_const.rs

@@ -0,0 +1,13 @@
+#![feature(min_generic_const_args, adt_const_params)]
+
+// Regression test for an ICE in privacy checking while walking the `T` qself
+// of `T::ASSOC` inside a tuple const argument.
+
+fn takes_tuple<const N: ()>() {}
+
+fn generic_caller<T, const N: u32>() {
+    takes_tuple::<{ (N, T::ASSOC) }>;
+    //~^ ERROR expected `()`, found `(N, T::ASSOC)`
+}
+
+fn main() {}

tests/ui/const-generics/mgca/tuple_expr_arg_unbounded_assoc_const.stderr

@@ -0,0 +1,8 @@
+error: expected `()`, found `(N, T::ASSOC)`
+  --> $DIR/tuple_expr_arg_unbounded_assoc_const.rs:9:21
+   |
+LL |     takes_tuple::<{ (N, T::ASSOC) }>;
+   |                     ^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+