Fixing Regression in #2353, #2359, #2325

Author: mikefarah

pkg/yqlib/operator_add_test.go

@@ -310,6 +310,13 @@ var addOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!map)::a: !cat Saturday, 15-Dec-01 at 6:00AM GMT\n",
 		},
 	},
+	{
+		skipDoc:     true,
+		description: "empty add shouldn't add",
+		document:    `[]`,
+		expression:  `.[]  | (.a + "cat")`,
+		expected:    []string{},
+	},
 	{
 		skipDoc:        true,
 		description:    "Add to empty",

pkg/yqlib/operators.go

@@ -118,7 +118,7 @@ func doCrossFunc(d *dataTreeNavigator, context Context, expressionNode *Expressi
 	}
 	log.Debugf("crossFunction LHS len: %v", lhs.MatchingNodes.Len())
 
-	if prefs.CalcWhenEmpty && lhs.MatchingNodes.Len() == 0 {
+	if prefs.CalcWhenEmpty && context.MatchingNodes.Len() > 0 && lhs.MatchingNodes.Len() == 0 {
 		err := resultsForRHS(d, context, nil, prefs, expressionNode.RHS, results)
 		if err != nil {
 			return Context{}, err

project-words.txt

@@ -255,4 +255,5 @@ zabbix
 tonumber
 noyaml
 nolint
-shortfile
+shortfile
+Unmarshalling