Fixed merge comments

pkg/yqlib/candidate_node.go

@@ -86,7 +86,14 @@ func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode) {
 	if n.Node.Style == 0 {
 		n.Node.Style = other.Node.Style
 	}
-	n.Node.FootComment = n.Node.FootComment + other.Node.FootComment
-	n.Node.HeadComment = n.Node.HeadComment + other.Node.HeadComment
-	n.Node.LineComment = n.Node.LineComment + other.Node.LineComment
+
+	if other.Node.FootComment != "" {
+		n.Node.FootComment = other.Node.FootComment
+	}
+	if other.Node.HeadComment != "" {
+		n.Node.HeadComment = other.Node.HeadComment
+	}
+	if other.Node.LineComment != "" {
+		n.Node.LineComment = other.Node.LineComment
+	}
 }

pkg/yqlib/operator_multiply.go

@@ -31,6 +31,7 @@ func multiply(preferences multiplyPreferences) func(d *dataTreeNavigator, contex
 			(lhs.Node.Kind == yaml.SequenceNode && rhs.Node.Kind == yaml.SequenceNode) {
 
 			var newBlank = lhs.CreateChild(nil, &yaml.Node{})
+
 			var newThing, err = mergeObjects(d, context, newBlank, lhs, multiplyPreferences{})
 			if err != nil {
 				return nil, err

pkg/yqlib/operator_multiply_test.go

@@ -4,6 +4,26 @@ import (
 	"testing"
 )
 
+var doc1 = `list:
+# Hi this is a comment.
+# Hello this is another comment.
+- "abc"`
+
+var doc2 = `list2:
+# This is yet another comment.
+# Indeed this is yet another comment.
+- "123"`
+
+var docExpected = `D0, P[], (!!map)::list:
+    # Hi this is a comment.
+    # Hello this is another comment.
+    - "abc"
+list2:
+    # This is yet another comment.
+    # Indeed this is yet another comment.
+    - "123"
+`
+
 var multiplyOperatorScenarios = []expressionScenario{
 	{
 		description: "Multiply integers",
@@ -12,6 +32,15 @@ var multiplyOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!int)::12\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   doc1,
+		document2:  doc2,
+		expression: `select(fi == 0) * select(fi == 1)`,
+		expected: []string{
+			docExpected,
+		},
+	},
 	{
 		skipDoc:    true,
 		expression: `3 * 4.5`,