Unexpected result with TRegex matching a unicode string. Is this a bug? - regex

Question

I am using delphi 10.1.
I have an unexpected result doing the following
procedure TForm1.FormCreate(Sender: TObject);
var
Match: TMatch;
Regex: TRegex;
Perl: TPerlRegEx;
const
s1 = 'Réaitaei: test123';
s2 = 'Réàààaitaei: test123';
s3 = 'Réàààààààààaitaei: test123';
pattern = '(.*): ';
begin
Regex := TRegex.Create(pattern);
Match := Regex.Match(s1);
Assert(Match.Success);
Memo1.Lines.Add(Match.Groups[1].Value);
Match := Regex.Match(s2);
Assert(Match.Success);
Memo1.Lines.Add(Match.Groups[1].Value);
Match := Regex.Match(s3);
Assert(Match.Success);
Memo1.Lines.Add(Match.Groups[1].Value);
Perl := TPerlRegEx.Create;
Perl.RegEx := pattern;
Perl.Compile;
Perl.Subject := s1;
Assert(Perl.Match);
Memo1.Lines.Add(Perl.Groups[1]);
Perl.Subject := s2;
Assert(Perl.Match);
Memo1.Lines.Add(Perl.Groups[1]);
Perl.Subject := s3;
Assert(Perl.Match);
Memo1.Lines.Add(Perl.Groups[1]);
end;
i get :
Réaitaei Réàààaitaei: t Réàààààààààaitaei: test
Réaitaei Réàààaitaei Réàààààààààaitaei
So TPerlRegex works but not TRegex when doc says that TRegex is just a wrapper to TPerlRegex.
Am I missing sth or it s a bug ?
I found a post from Marco Cantu saying that since delphi xe7, delphi uses pcre 8.35 so I am not expecting any problem from using unicode.

Answer 1

Looks like RSP-17697 solves this issue in Tokyo 10.2.1. When you run a compare on the relevant units you can see that TBytes was changed to Unicode String. I've checked my re-used RegEx and its not affected but for anyone not sure and using Berlin or lower use the class method to assure all works: TRegex.Match('Réàààààààààaitaei: test123', '(.*): ').Groups[1].Value = 'Réàààààààààaitaei'
That would be one heck of a bug to hunt down