From f03005f86d27e25da8745a3d6526ddaef4b2514b Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Fri, 20 Nov 2020 15:29:53 +1100
Subject: [PATCH] Fixed boolean ops

---
 pkg/yqlib/doc/Assign Operator.md    |  4 +--
 pkg/yqlib/operator_booleans.go      | 55 +++++++++++++++++++----------
 pkg/yqlib/operator_booleans_test.go |  4 +--
 3 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/pkg/yqlib/doc/Assign Operator.md b/pkg/yqlib/doc/Assign Operator.md
index 0dadc5bf..f5b893ba 100644
--- a/pkg/yqlib/doc/Assign Operator.md	
+++ b/pkg/yqlib/doc/Assign Operator.md	
@@ -6,7 +6,7 @@ Which will assign the LHS node values to the RHS node values. The RHS expression
 ### relative form: `|=`
 This will do a similar thing to the plain form, however, the RHS expression is run against _the LHS nodes_. This is useful for updating values based on old values, e.g. increment.
 ## Examples
-### Update parent to be the child value
+### Update node to be the child value
 Given a sample.yml file of:
 ```yaml
 a:
@@ -23,7 +23,7 @@ a:
   g: foof
 ```
 
-### Update to be the sibling value
+### Update node to be the sibling value
 Given a sample.yml file of:
 ```yaml
 a:
diff --git a/pkg/yqlib/operator_booleans.go b/pkg/yqlib/operator_booleans.go
index 28e2fbac..ee7f6931 100644
--- a/pkg/yqlib/operator_booleans.go
+++ b/pkg/yqlib/operator_booleans.go
@@ -3,7 +3,7 @@ package yqlib
 import (
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 func isTruthy(c *CandidateNode) (bool, error) {
@@ -25,9 +25,42 @@ func isTruthy(c *CandidateNode) (bool, error) {
 
 type boolOp func(bool, bool) bool
 
+func performBoolOp(results *list.List, lhs *list.List, rhs *list.List, op boolOp) error {
+	for lhsChild := lhs.Front(); lhsChild != nil; lhsChild = lhsChild.Next() {
+		lhsCandidate := lhsChild.Value.(*CandidateNode)
+		lhsTrue, errDecoding := isTruthy(lhsCandidate)
+		if errDecoding != nil {
+			return errDecoding
+		}
+
+		for rhsChild := rhs.Front(); rhsChild != nil; rhsChild = rhsChild.Next() {
+			rhsCandidate := rhsChild.Value.(*CandidateNode)
+			rhsTrue, errDecoding := isTruthy(rhsCandidate)
+			if errDecoding != nil {
+				return errDecoding
+			}
+			boolResult := createBooleanCandidate(lhsCandidate, op(lhsTrue, rhsTrue))
+			results.PushBack(boolResult)
+		}
+	}
+	return nil
+}
+
 func booleanOp(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode, op boolOp) (*list.List, error) {
 	var results = list.New()
 
+	if matchingNodes.Len() == 0 {
+		lhs, err := d.GetMatchingNodes(list.New(), pathNode.Lhs)
+		if err != nil {
+			return nil, err
+		}
+		rhs, err := d.GetMatchingNodes(list.New(), pathNode.Rhs)
+		if err != nil {
+			return nil, err
+		}
+		return results, performBoolOp(results, lhs, rhs, op)
+	}
+
 	for el := matchingNodes.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		lhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Lhs)
@@ -39,23 +72,9 @@ func booleanOp(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTre
 			return nil, err
 		}
 
-		for lhsChild := lhs.Front(); lhsChild != nil; lhsChild = lhsChild.Next() {
-			lhsCandidate := lhsChild.Value.(*CandidateNode)
-			lhsTrue, errDecoding := isTruthy(lhsCandidate)
-			if errDecoding != nil {
-				return nil, errDecoding
-			}
-
-			for rhsChild := rhs.Front(); rhsChild != nil; rhsChild = rhsChild.Next() {
-				rhsCandidate := rhsChild.Value.(*CandidateNode)
-				rhsTrue, errDecoding := isTruthy(rhsCandidate)
-				if errDecoding != nil {
-					return nil, errDecoding
-				}
-				boolResult := createBooleanCandidate(lhsCandidate, op(lhsTrue, rhsTrue))
-
-				results.PushBack(boolResult)
-			}
+		err = performBoolOp(results, lhs, rhs, op)
+		if err != nil {
+			return nil, err
 		}
 
 	}
diff --git a/pkg/yqlib/operator_booleans_test.go b/pkg/yqlib/operator_booleans_test.go
index 6c9b1dea..12e65c51 100644
--- a/pkg/yqlib/operator_booleans_test.go
+++ b/pkg/yqlib/operator_booleans_test.go
@@ -24,8 +24,8 @@ var booleanOperatorScenarios = []expressionScenario{
 		description: "Matching nodes with select, equals and or",
 		expression:  `.[] | select(.a == "cat" or .b == "dog")`,
 		expected: []string{
-			"D0, P[], (!!map)::{a: bird, b: dog}\n",
-			"D0, P[], (!!map)::{a: cat, b: fly}\n",
+			"D0, P[0], (!!map)::{a: bird, b: dog}\n",
+			"D0, P[2], (!!map)::{a: cat, b: fly}\n",
 		},
 	},
 	{