Issue 60168. Set enclosingFragment for JoinPatternVariableElementImpl when merging LogicalOrPattern.

Bug: #60168
Change-Id: Id77cd5975c6a090237eb011bb4eca91e18fedf2b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/410840
Reviewed-by: Phil Quitslund <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/element/element.dart

@@ -7914,6 +7914,10 @@ class LocalVariableElementImpl extends NonParameterVariableElementImpl
   @override
   Fragment get enclosingFragment => enclosingElement3 as Fragment;
 
+  set enclosingFragment(Fragment value) {
+    enclosingElement3 = value as Element;
+  }
+
   @override
   String get identifier {
     return '$name$nameOffset';

pkg/analyzer/lib/src/dart/resolver/resolution_visitor.dart

@@ -1991,8 +1991,7 @@ class _VariableBinder
             .map((e) => e.inconsistency),
       ),
     )
-          ..enclosingElement3 =
-              first.firstFragment.enclosingFragment!.element.asElement!
+          ..enclosingFragment = first.firstFragment.enclosingFragment!
           ..type = InvalidTypeImpl.instance)
         .element;
   }

pkg/analyzer/test/src/dart/resolution/logical_or_pattern_test.dart

@@ -74,6 +74,43 @@ LogicalOrPattern
     name: _
     matchedValueType: dynamic
   matchedValueType: dynamic
+''');
+  }
+
+  test_switchCase_topLevel3() async {
+    // https://github.com/dart-lang/sdk/issues/60168
+    await resolveTestCode(r'''
+var _ = switch (0) {
+  var a || var a || var a => 0,
+};
+''');
+
+    var node = findNode.singleGuardedPattern.pattern;
+    assertResolvedNodeText(node, r'''
+LogicalOrPattern
+  leftOperand: LogicalOrPattern
+    leftOperand: DeclaredVariablePattern
+      keyword: var
+      name: a
+      declaredElement: hasImplicitType a@27
+        type: int
+      matchedValueType: int
+    operator: ||
+    rightOperand: DeclaredVariablePattern
+      keyword: var
+      name: a
+      declaredElement: hasImplicitType a@36
+        type: int
+      matchedValueType: int
+    matchedValueType: int
+  operator: ||
+  rightOperand: DeclaredVariablePattern
+    keyword: var
+    name: a
+    declaredElement: hasImplicitType a@45
+      type: int
+    matchedValueType: int
+  matchedValueType: int
 ''');
   }
 }