Are you sure your strings are text strings when you apply quotemeta? 

use Devel::Peek;
use Encode '_utf8_off';

my $u = "abc\x{5555}abc";
my $qu = quotemeta $u;       # text (UTF-8)

Dump $u;
Dump $qu;

my $s = $u;  _utf8_off($s);
my $qs = quotemeta $s;       # bytes

Dump $s;
Dump $qs;

__END__
SV = PV(0x63d150) at 0x65eb90
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x6550f0 "abc\345\225\225abc"\0 [UTF8 "abc\x{5555}abc"]
  CUR = 9
  LEN = 16
SV = PV(0x63d120) at 0x65eb30
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x662e60 "abc\345\225\225abc"\0 [UTF8 "abc\x{5555}abc"]
  CUR = 9
  LEN = 16
SV = PVMG(0x697c58) at 0x65eb10
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK)
  IV = 0
  NV = 0
  PV = 0x6aa700 "abc\345\225\225abc"\0
  CUR = 9
  LEN = 16
SV = PV(0x63d120) at 0x65eb00
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK)
  PV = 0x66a030 "abc\\\345\\\225\\\225abc"\0
  CUR = 12
  LEN = 16

[download]

As you can see, no quoting is being done except when the string is treated as bytes.

In reply to Re: postgres reg expression quoting (again) by almut
in thread postgres reg expression quoting (again) by zdzieblo

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