From 1bb19dfcc505d00f51a60d42bcd09ee56fb1620c Mon Sep 17 00:00:00 2001
From: Jordan Liggitt <jliggitt@redhat.com>
Date: Thu, 11 May 2017 13:15:30 -0400
Subject: [PATCH] Revert "Ensure empty serialized slices are zero-length, not
 null"

---
 .../conversion-gen/generators/conversion.go   | 27 ++-----------------
 1 file changed, 2 insertions(+), 25 deletions(-)

diff --git a/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go b/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go
index 9a219fcd69d..dfb065e58e7 100644
--- a/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go
+++ b/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go
@@ -29,8 +29,6 @@ import (
 	"k8s.io/gengo/namer"
 	"k8s.io/gengo/types"
 
-	"reflect"
-
 	"github.com/golang/glog"
 )
 
@@ -792,15 +790,6 @@ func (g *genConversion) doStruct(inType, outType *types.Type, sw *generator.Snip
 			outMemberType = &copied
 		}
 
-		// Determine if our destination field is a slice that should be output when empty.
-		// If it is, ensure a nil source slice converts to a zero-length destination slice.
-		// See http://issue.k8s.io/43203
-		persistEmptySlice := false
-		if outMemberType.Kind == types.Slice {
-			jsonTag := reflect.StructTag(outMember.Tags).Get("json")
-			persistEmptySlice = len(jsonTag) > 0 && !strings.Contains(jsonTag, ",omitempty")
-		}
-
 		args := argsFromType(inMemberType, outMemberType).With("name", inMember.Name)
 
 		// try a direct memory copy for any type that has exactly equivalent values
@@ -816,15 +805,7 @@ func (g *genConversion) doStruct(inType, outType *types.Type, sw *generator.Snip
 				sw.Do("out.$.name$ = *(*$.outType|raw$)($.Pointer|raw$(&in.$.name$))\n", args)
 				continue
 			case types.Slice:
-				if persistEmptySlice {
-					sw.Do("if in.$.name$ == nil {\n", args)
-					sw.Do("out.$.name$ = make($.outType|raw$, 0)\n", args)
-					sw.Do("} else {\n", nil)
-					sw.Do("out.$.name$ = *(*$.outType|raw$)($.Pointer|raw$(&in.$.name$))\n", args)
-					sw.Do("}\n", nil)
-				} else {
-					sw.Do("out.$.name$ = *(*$.outType|raw$)($.Pointer|raw$(&in.$.name$))\n", args)
-				}
+				sw.Do("out.$.name$ = *(*$.outType|raw$)($.Pointer|raw$(&in.$.name$))\n", args)
 				continue
 			}
 		}
@@ -874,11 +855,7 @@ func (g *genConversion) doStruct(inType, outType *types.Type, sw *generator.Snip
 			sw.Do("in, out := &in.$.name$, &out.$.name$\n", args)
 			g.generateFor(inMemberType, outMemberType, sw)
 			sw.Do("} else {\n", nil)
-			if persistEmptySlice {
-				sw.Do("out.$.name$ = make($.outType|raw$, 0)\n", args)
-			} else {
-				sw.Do("out.$.name$ = nil\n", args)
-			}
+			sw.Do("out.$.name$ = nil\n", args)
 			sw.Do("}\n", nil)
 		case types.Struct:
 			if g.isDirectlyAssignable(inMemberType, outMemberType) {