Unrolled build for #156497

Rollup merge of #156497 - lokirithm:fix-155516, r=cjgillot

fix-155516: Don't suggest wrong unwrap expect

Fixes #155516

r? Kivooeo

Author: rust-timer

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -2272,6 +2272,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expected: Ty<'tcx>,
         found: Ty<'tcx>,
     ) -> bool {
+        // don't suggest missing `.expect()` or `?` in destructuring assignments LHS.
+        // If the immediate parent is an Assign Expr, and the LHS and the RHS of that Expr
+        // overlap with each other, it's guaranteed that the expression came from desugaring
+        // a destructuring assignment.
+        let parent_node = self.tcx.parent_hir_node(expr.hir_id);
+        if let hir::Node::Expr(e) = parent_node
+            && let hir::ExprKind::Assign(lhs, rhs, _) = e.kind
+            && rhs.hir_id == expr.hir_id
+            && lhs.span.overlaps(rhs.span)
+        {
+            return false;
+        }
+
         let ty::Adt(adt, args) = found.kind() else {
             return false;
         };

tests/ui/destructuring-assignment/dont-suggest-wrong-expect-suggestion.rs

@@ -0,0 +1,19 @@
+//! regression test for <https://github.com/rust-lang/rust/issues/155516>
+
+struct NamedStruct {
+    opt_field: Option<usize>,
+    res_field: Result<usize, ()>,
+}
+
+fn main() {
+    let a: usize;
+    let b: usize;
+
+    NamedStruct {
+        opt_field: a, //~ ERROR mismatched types
+        res_field: b, //~ ERROR mismatched types
+    } = NamedStruct {
+        opt_field: Some(0),
+        res_field: Ok(42_usize),
+    };
+}

tests/ui/destructuring-assignment/dont-suggest-wrong-expect-suggestion.stderr

@@ -0,0 +1,27 @@
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-wrong-expect-suggestion.rs:13:20
+   |
+LL |     let a: usize;
+   |            ----- expected due to this type
+...
+LL |         opt_field: a,
+   |                    ^ expected `usize`, found `Option<usize>`
+   |
+   = note: expected type `usize`
+              found enum `Option<usize>`
+
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-wrong-expect-suggestion.rs:14:20
+   |
+LL |     let b: usize;
+   |            ----- expected due to this type
+...
+LL |         res_field: b,
+   |                    ^ expected `usize`, found `Result<usize, ()>`
+   |
+   = note: expected type `usize`
+              found enum `Result<usize, ()>`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.