Fixed merge bug https://github.com/mikefarah/yq/issues/880

pkg/yqlib/context.go

@@ -66,3 +66,9 @@ func (n *Context) ReadOnlyClone() Context {
 	clone.DontAutoCreate = true
 	return clone
 }
+
+func (n *Context) WritableClone() Context {
+	clone := n.Clone()
+	clone.DontAutoCreate = false
+	return clone
+}

pkg/yqlib/operator_multiply.go

@@ -32,11 +32,11 @@ func multiply(preferences multiplyPreferences) func(d *dataTreeNavigator, contex
 
 			var newBlank = lhs.CreateChild(nil, &yaml.Node{})
 
-			var newThing, err = mergeObjects(d, context, newBlank, lhs, multiplyPreferences{})
+			var newThing, err = mergeObjects(d, context.WritableClone(), newBlank, lhs, multiplyPreferences{})
 			if err != nil {
 				return nil, err
 			}
-			return mergeObjects(d, context, newThing, rhs, preferences)
+			return mergeObjects(d, context.WritableClone(), newThing, rhs, preferences)
 		} else if lhs.Node.Tag == "!!int" && rhs.Node.Tag == "!!int" {
 			return multiplyIntegers(lhs, rhs)
 		} else if (lhs.Node.Tag == "!!int" || lhs.Node.Tag == "!!float") && (rhs.Node.Tag == "!!int" || rhs.Node.Tag == "!!float") {

pkg/yqlib/operator_multiply_test.go

@@ -47,6 +47,20 @@ var multiplyOperatorScenarios = []expressionScenario{
 			docExpected,
 		},
 	},
+	{
+		skipDoc:    true,
+		expression: `.x =  {"things": "whatever"} * {}`,
+		expected: []string{
+			"D0, P[], ()::x:\n    things: whatever\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		expression: `.x = {} * {"things": "whatever"}`,
+		expected: []string{
+			"D0, P[], ()::x:\n    things: whatever\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		expression: `3 * 4.5`,