diff --git a/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart b/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart
index 03877e465e3..d8cd2d89110 100644
--- a/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart
@@ -2984,7 +2984,7 @@ class _FlowAnalysisImpl<Node, Statement extends Node, Expression, Variable,
     // common base class.  See https://github.com/dart-lang/sdk/issues/43725.
     _SimpleContext<Variable, Type> context =
         _stack.removeLast() as _SimpleContext<Variable, Type>;
-    _current = _join(_current, context._previous);
+    _current = _merge(_current, context._previous);
   }
 
   @override
@@ -2992,6 +2992,7 @@ class _FlowAnalysisImpl<Node, Statement extends Node, Expression, Variable,
       Expression leftHandSide, Type leftHandSideType) {
     ExpressionInfo<Variable, Type> lhsInfo = _getExpressionInfo(leftHandSide);
     FlowModel<Variable, Type> promoted;
+    _current = _current.split();
     if (lhsInfo is _VariableReadInfo<Variable, Type>) {
       ExpressionInfo<Variable, Type> promotionInfo =
           _current.tryMarkNonNullable(typeOperations, lhsInfo._variable);
@@ -3156,12 +3157,13 @@ class _FlowAnalysisImpl<Node, Statement extends Node, Expression, Variable,
     // common base class.  See https://github.com/dart-lang/sdk/issues/43725.
     _SimpleContext<Variable, Type> context =
         _stack.removeLast() as _SimpleContext<Variable, Type>;
-    _current = _join(_current, context._previous);
+    _current = _merge(_current, context._previous);
   }
 
   @override
   bool nullAwareAccess_rightBegin(Expression target, Type targetType) {
     assert(targetType != null);
+    _current = _current.split();
     _stack.add(new _NullAwareAccessContext<Variable, Type>(_current));
     if (target != null) {
       ExpressionInfo<Variable, Type> targetInfo = _getExpressionInfo(target);
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/promotion_in_dead_code.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/promotion_in_dead_code.dart
index e8dfacdb1ea..3e56036d41c 100644
--- a/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/promotion_in_dead_code.dart
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/promotion_in_dead_code.dart
@@ -6,6 +6,10 @@
 // promotion continue to function properly even when used inside unreachable
 // code.
 
+abstract class C {
+  void f(Object x, Object y);
+}
+
 conditionalIs(Object o) {
   return;
   o is int ? null : throw 'bad';
@@ -92,3 +96,15 @@ ifIsNot_mapElement(Object o) {
   ({if (o is! int) 0: throw 'x'});
   /*int*/ o;
 }
+
+ifNull(Object o, Object? p, Object q, void Function(Object, Object) f) {
+  return;
+  (o is int ? p : throw 'x') ?? f(o = q, throw 'x');
+  /*int*/ o;
+}
+
+nullAwareAccess(Object o, C? p, Object q) {
+  return;
+  (o is int ? p : throw 'x')?.f(o = q, throw 'x');
+  /*int*/ o;
+}