Panic when converting a struct that embeds a pointer to another struct to Unstructured #172
Description
The following setup can lead to a panic. The issue seems to be with embedding a pointer to a struct, when using runtime.DefaultUnstructuredConverter.ToUnstructured.
type A struct {
*B `json:",inline"`
}
type B struct {
Foo string `json:"foo"`
}The panic observed is:
... Panic: reflect: NumField of non-struct type *v2.CiliumNetworkPolicy (PC=0x46A7A8)
/usr/lib/go/src/runtime/panic.go:975
in gopanic
/usr/lib/go/src/reflect/type.go:974
in rtype.NumField
/home/chris/code/cilium/cilium/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go:146
in buildStructCacheEntry
/home/chris/code/cilium/cilium/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go:153
in buildStructCacheEntry
/home/chris/code/cilium/cilium/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go:119
in typeReflectEntryOf
/home/chris/code/cilium/cilium/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go:94
in TypeReflectEntryOf
/home/chris/code/cilium/cilium/vendor/k8s.io/apimachinery/pkg/runtime/converter.go:480
in toUnstructured
/home/chris/code/cilium/cilium/vendor/k8s.io/apimachinery/pkg/runtime/converter.go:413
in unstructuredConverter.ToUnstructured
unknown_fields.go:102
in detectUnknownFields
validator.go:138
in NPValidator.ValidateCCNP
validator_test.go:189
in CNPValidationSuite.Test_GoodCCNP
/usr/lib/go/src/reflect/value.go:336
in Value.Call
/usr/lib/go/src/runtime/asm_amd64.s:1374
in goexit
The following patch fixes the issue:
diff --git a/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go
index 49e6dd169..ff16bd52f 100644
--- a/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go
+++ b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go
@@ -150,7 +150,11 @@ func buildStructCacheEntry(t reflect.Type, infos map[string]*FieldCacheEntry, fi
continue
}
if isInline {
- buildStructCacheEntry(field.Type, infos, append(fieldPath, field.Index))
+ e := field.Type
+ if field.Type.Kind() == reflect.Ptr {
+ e = field.Type.Elem()
+ }
+ buildStructCacheEntry(e, infos, append(fieldPath, field.Index))
continue
}
info := &FieldCacheEntry{JsonName: jsonName, isOmitEmpty: isOmitempty, fieldPath: append(fieldPath, field.Index), fieldType: field.Type}