Merge pull request #95933 from brianpursley/kubernetes-95882

Fix bug in JSON path parser where an error occurs when a range is empty

Kubernetes-commit: cd99c63570eb1489dd631c12ea86db708dbdcd59

Godeps/Godeps.json

@@ -448,11 +448,11 @@
 		},
 		{
 			"ImportPath": "k8s.io/api",
-			"Rev": "7a95b569f5ff"
+			"Rev": "18d4659ab40b"
 		},
 		{
 			"ImportPath": "k8s.io/apimachinery",
-			"Rev": "8046191f3410"
+			"Rev": "1aed267868af"
 		},
 		{
 			"ImportPath": "k8s.io/gengo",

go.mod

@@ -26,14 +26,14 @@ require (
 	golang.org/x/net v0.0.0-20200707034311-ab3426394381
 	golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6
 	golang.org/x/time v0.0.0-20191024005414-555d28b269f0
-	k8s.io/api v0.0.0-20201102202211-7a95b569f5ff
+	k8s.io/api v0.0.0-20201103002210-18d4659ab40b
-	k8s.io/apimachinery v0.0.0-20201102202032-8046191f3410
+	k8s.io/apimachinery v0.0.0-20201103082028-1aed267868af
 	k8s.io/klog/v2 v2.2.0
 	k8s.io/utils v0.0.0-20200729134348-d5654de09c73
 	sigs.k8s.io/yaml v1.2.0
 )
 
 replace (
-	k8s.io/api => k8s.io/api v0.0.0-20201102202211-7a95b569f5ff
+	k8s.io/api => k8s.io/api v0.0.0-20201103002210-18d4659ab40b
-	k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20201102202032-8046191f3410
+	k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20201103082028-1aed267868af
 )

go.sum

@@ -335,8 +335,8 @@ honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWh
 honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
-k8s.io/api v0.0.0-20201102202211-7a95b569f5ff/go.mod h1:DvHvdeQUPLTohsRVYB2Fd49FYz7l0WWEnJBD4BrP9Pc=
+k8s.io/api v0.0.0-20201103002210-18d4659ab40b/go.mod h1:b+K6RbdbECmbVaw11+iMzmt6th7YpfdynGdh/HKUa54=
-k8s.io/apimachinery v0.0.0-20201102202032-8046191f3410/go.mod h1:6s3VNb000AUbBIxR7q3WHlbBwfpEGqIJsCG5gIX+0LI=
+k8s.io/apimachinery v0.0.0-20201103082028-1aed267868af/go.mod h1:6s3VNb000AUbBIxR7q3WHlbBwfpEGqIJsCG5gIX+0LI=
 k8s.io/gengo v0.0.0-20200413195148-3a45101e95ac/go.mod h1:ezvh/TsK7cY6rbqRK0oQQ8IAqLxYwwyPxAX1Pzy0ii0=
 k8s.io/klog/v2 v2.0.0/go.mod h1:PBfzABfn139FHAV07az/IF9Wp1bkk3vpT2XSJ76fSDE=
 k8s.io/klog/v2 v2.2.0 h1:XRvcwJozkgZ1UQJmfMGpvRthQHOvihEhYtDfAaxMz/A=

util/jsonpath/jsonpath.go

@@ -103,13 +103,23 @@ func (j *JSONPath) FindResults(data interface{}) ([][]reflect.Value, error) {
 		if j.beginRange > 0 {
 			j.beginRange--
 			j.inRange++
-			for _, value := range results {
+			if len(results) > 0 {
+				for _, value := range results {
+					j.parser.Root.Nodes = nodes[i+1:]
+					nextResults, err := j.FindResults(value.Interface())
+					if err != nil {
+						return nil, err
+					}
+					fullResult = append(fullResult, nextResults...)
+				}
+			} else {
+				// If the range has no results, we still need to process the nodes within the range
+				// so the position will advance to the end node
 				j.parser.Root.Nodes = nodes[i+1:]
-				nextResults, err := j.FindResults(value.Interface())
+				_, err := j.FindResults(nil)
 				if err != nil {
 					return nil, err
 				}
-				fullResult = append(fullResult, nextResults...)
 			}
 			j.inRange--
 

util/jsonpath/jsonpath_test.go

@@ -393,6 +393,21 @@ func TestKubernetes(t *testing.T) {
 	testJSONPathSortOutput(randomPrintOrderTests, t)
 }
 
+func TestEmptyRange(t *testing.T) {
+	var input = []byte(`{"items":[]}`)
+	var emptyList interface{}
+	err := json.Unmarshal(input, &emptyList)
+	if err != nil {
+		t.Error(err)
+	}
+
+	tests := []jsonpathTest{
+		{"empty range", `{range .items[*]}{.metadata.name}{end}`, &emptyList, "", false},
+		{"empty nested range", `{range .items[*]}{.metadata.name}{":"}{range @.spec.containers[*]}{.name}{","}{end}{"+"}{end}`, &emptyList, "", false},
+	}
+	testJSONPath(tests, true, t)
+}
+
 func TestNestedRanges(t *testing.T) {
 	var input = []byte(`{
 		"items": [