Merge pull request rust-lang#20905 from ShoyuVanilla/array-inhabit

fix: Fix a bug on inhabitedness checks for arrays

Author: ChayimFriedman2

src/tools/rust-analyzer/crates/hir-ty/src/inhabitedness.rs

@@ -90,7 +90,7 @@ impl<'db> TypeVisitor<DbInterner<'db>> for UninhabitedFrom<'_, 'db> {
             TyKind::Tuple(..) => ty.super_visit_with(self),
             TyKind::Array(item_ty, len) => match try_const_usize(self.infcx.interner.db, len) {
                 Some(0) | None => CONTINUE_OPAQUELY_INHABITED,
-                Some(1..) => item_ty.super_visit_with(self),
+                Some(1..) => item_ty.visit_with(self),
             },
             _ => CONTINUE_OPAQUELY_INHABITED,
         };

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/non_exhaustive_let.rs

@@ -152,6 +152,58 @@ impl<T> Deref for Foo<T> {
 fn test(x: Foo<(i32, bool)>) {
     let (_a, _b): &(i32, bool) = &x;
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn uninhabited_variants() {
+        check_diagnostics(
+            r#"
+//- minicore: result
+enum Infallible {}
+
+trait Foo {
+    type Bar;
+}
+
+struct Wrapper<T> {
+    error: T,
+}
+
+struct FooWrapper<T: Foo> {
+    error: T::Bar,
+}
+
+fn foo<T: Foo<Bar = Infallible>>(result: Result<T, T::Bar>) -> T {
+    let Ok(ok) = result;
+    ok
+}
+
+fn bar<T: Foo<Bar = Infallible>>(result: Result<T, (T::Bar,)>) -> T {
+    let Ok(ok) = result;
+    ok
+}
+
+fn baz<T: Foo<Bar = Infallible>>(result: Result<T, Wrapper<T::Bar>>) -> T {
+    let Ok(ok) = result;
+    ok
+}
+
+fn qux<T: Foo<Bar = Infallible>>(result: Result<T, FooWrapper<T>>) -> T {
+    let Ok(ok) = result;
+    ok
+}
+
+fn quux<T: Foo<Bar = Infallible>>(result: Result<T, [T::Bar; 1]>) -> T {
+    let Ok(ok) = result;
+    ok
+}
+
+fn corge<T: Foo<Bar = Infallible>>(result: Result<T, (i32, T::Bar)>) -> T {
+    let Ok(ok) = result;
+    ok
+}
 "#,
         );
     }