Fixed nil RHS bug in alternative operator #838

pkg/yqlib/operator_alternative_test.go

@@ -5,6 +5,12 @@ import (
 )
 
 var alternativeOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		expression: `.b // .c`,
+		document:   `a: bridge`,
+		expected:   []string{},
+	},
 	{
 		skipDoc:    true,
 		expression: `(.b // "hello") as $x`,

pkg/yqlib/operator_booleans_test.go

@@ -12,6 +12,14 @@ var booleanOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!bool)::true\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   "b: hi",
+		expression: `.a or .c`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   "b: hi",

pkg/yqlib/operator_equals_test.go

@@ -5,6 +5,13 @@ import (
 )
 
 var equalsOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		expression: ".a == .b",
+		expected: []string{
+			"D0, P[], (!!bool)::true\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   "cat",

pkg/yqlib/operators.go

@@ -31,7 +31,9 @@ func resultsForRhs(d *dataTreeNavigator, context Context, lhsCandidate *Candidat
 		if err != nil {
 			return err
 		}
-		results.PushBack(resultCandidate)
+		if resultCandidate != nil {
+			results.PushBack(resultCandidate)
+		}
 		return nil
 	}
 
@@ -42,7 +44,9 @@ func resultsForRhs(d *dataTreeNavigator, context Context, lhsCandidate *Candidat
 		if err != nil {
 			return err
 		}
-		results.PushBack(resultCandidate)
+		if resultCandidate != nil {
+			results.PushBack(resultCandidate)
+		}
 	}
 	return nil
 }