move HasConflicts to shareable location

pkg/util/strategicpatch/patch.go

@@ -827,3 +827,44 @@ func sliceElementType(slices ...[]interface{}) (reflect.Type, error) {
 
 	return prevType, nil
 }
+
+// HasConflicts returns true if the left and right JSON interface objects overlap with
+// different values in any key.  The code will panic if an unrecognized type is passed
+// (anything not returned by a JSON decode).  All keys are required to be strings.
+// Since patches of the same Type have congruent keys, this is valid for multiple patch
+// types.
+func HasConflicts(left, right interface{}) (bool, error) {
+	switch typedLeft := left.(type) {
+	case map[string]interface{}:
+		switch typedRight := right.(type) {
+		case map[string]interface{}:
+			for key, leftValue := range typedLeft {
+				rightValue, ok := typedRight[key]
+				if !ok {
+					return false, nil
+				}
+				return HasConflicts(leftValue, rightValue)
+			}
+			return false, nil
+		default:
+			return true, nil
+		}
+	case []interface{}:
+		switch typedRight := right.(type) {
+		case []interface{}:
+			if len(typedLeft) != len(typedRight) {
+				return true, nil
+			}
+			for i := range typedLeft {
+				return HasConflicts(typedLeft[i], typedRight[i])
+			}
+			return false, nil
+		default:
+			return true, nil
+		}
+	case string, float64, bool, int, int64, nil:
+		return !reflect.DeepEqual(left, right), nil
+	default:
+		return true, fmt.Errorf("unknown type: %v", reflect.TypeOf(left))
+	}
+}