Fixed passing of readonly context in pipe

pkg/yqlib/operator_collect_object_test.go

@@ -14,6 +14,13 @@ var collectObjectOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!map)::dog: great\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		expression: `({} + {}) | (.b = 3)`,
+		expected: []string{
+			"D0, P[], (!!map)::b: 3\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   "a: []",

pkg/yqlib/operator_pipe.go

@@ -5,12 +5,12 @@ func pipeOperator(d *dataTreeNavigator, context Context, expressionNode *Express
 	if expressionNode.LHS.Operation.OperationType == assignVariableOpType {
 		return variableLoop(d, context, expressionNode)
 	}
-
 	lhs, err := d.GetMatchingNodes(context, expressionNode.LHS)
 	if err != nil {
 		return Context{}, err
 	}
-	rhs, err := d.GetMatchingNodes(lhs, expressionNode.RHS)
+	rhsContext := context.ChildContext(lhs.MatchingNodes)
+	rhs, err := d.GetMatchingNodes(rhsContext, expressionNode.RHS)
 	if err != nil {
 		return Context{}, err
 	}

pkg/yqlib/operator_pipe_test.go

@@ -21,6 +21,14 @@ var pipeOperatorScenarios = []expressionScenario{
 			"D0, P[], (doc)::{a: cat, b: dog, c: same}\n",
 		},
 	},
+	{
+		skipDoc:     true,
+		description: "Don't pass readonly context",
+		expression:  `(3 + 4) | ({} | .b = "dog")`,
+		expected: []string{
+			"D0, P[], (!!map)::b: dog\n",
+		},
+	},
 }
 
 func TestPipeOperatorScenarios(t *testing.T) {