changes in JSON::XS quoting of scalar(@emptyarray)

gistfile1.txt

perl-5.32.1
==========
Perl 5.032001
JSON::XS 4.03
Dumping $resp:
SV = IV(0x5639baf18fe8) at 0x5639baf18ff8
  REFCNT = 1
  FLAGS = (ROK)
  RV = 0x5639baeb2358
  SV = PVHV(0x5639baeb7b70) at 0x5639baeb2358
    REFCNT = 1
    FLAGS = (SHAREKEYS)
    ARRAY = 0x5639baf349b0  (0:7, 1:1)
    hash quality = 100.0%
    KEYS = 1
    FILL = 1
    MAX = 7
    Elt "foo" HASH = 0x6263db87
    SV = PVNV(0x5639baeb10f0) at 0x5639baeb2610
      REFCNT = 1
      FLAGS = (IOK,NOK,POK,pIOK,pNOK,pPOK)
      IV = 0
      NV = 0
      PV = 0x5639baf5ebc0 "0"\0
      CUR = 1
      LEN = 10
{"foo":"0"}

perl-5.28.3
==========
Perl 5.028003
JSON::XS 4.03
Dumping $resp:
SV = IV(0x55618f406f48) at 0x55618f406f58
  REFCNT = 1
  FLAGS = (ROK)
  RV = 0x55618f3ac328
  SV = PVHV(0x55618f3b2770) at 0x55618f3ac328
    REFCNT = 1
    FLAGS = (SHAREKEYS)
    ARRAY = 0x55618f42b590  (0:7, 1:1)
    hash quality = 100.0%
    KEYS = 1
    FILL = 1
    MAX = 7
    Elt "foo" HASH = 0xf5030846
    SV = PVNV(0x55618f3ab0f0) at 0x55618f3c6020
      REFCNT = 1
      FLAGS = (IOK,NOK,POK,pIOK,pNOK,pPOK)
      IV = 0
      NV = 0
      PV = 0x55618f45b800 "0"\0
      CUR = 1
      LEN = 10
{"foo":"0"}

perl-5.26.3
==========
Perl 5.026003
JSON::XS 4.03
Dumping $resp:
SV = IV(0x5587840c26b8) at 0x5587840c26c8
  REFCNT = 1
  FLAGS = (ROK)
  RV = 0x558784080328
  SV = PVHV(0x558784086d60) at 0x558784080328
    REFCNT = 1
    FLAGS = (SHAREKEYS)
    ARRAY = 0x5587840b70c0  (0:7, 1:1)
    hash quality = 100.0%
    KEYS = 1
    FILL = 1
    MAX = 7
    Elt "foo" HASH = 0x61886f7a
    SV = IV(0x5587840944e0) at 0x5587840944f0
      REFCNT = 1
      FLAGS = (IOK,pIOK)
      IV = 0
{"foo":0}

test-simple.pl

#!/usr/bin/env perl
use strict;
use warnings;
use Devel::Peek;
use JSON::XS;

print "Perl $]\n";
print "JSON::XS $JSON::XS::VERSION\n";

my @bar = ();

my $resp = {
	foo => scalar(@bar)
};

warn "Dumping \$resp:\n";
Dump($resp);

print encode_json($resp), "\n";