problem with string concatenation with parboiled java 1.4.1

[plamaiziere]

Hello,

I use parboiled since a long time to parse some routers configuration files. I've got a lot of test cases to test the parsers results.
With version 1.4.1 few test cases fail when, in the parser rules, i use string concatenation wih the '+' operator.
If I replace the '+' operator with the String.concat method this works fine.

Exemple:

public Rule AceTcpOldFlag() {
return
	Sequence(
		FirstOf(
			String("ack"),
			String("fin"),
			String("psh"),
			String("rst"),
			String("syn"),
			String("urg")
		),
		_ace.getTcpFlags().add("+" + match()), // ace.getTcpflags is a String list
		_ace.setTcpKeyword("match-any"),
		SkipSpaces()
	);
}

In a test case for this rule like "ack rst psh fin syn urg", flags are set with the match() value, (ie ack, fin, psh etc), but without the "+" at the start as if the string + operator does nothing.
If I replace the + operator with String.concat it works fine : _ace.getTcpFlags().add("+".concat(match()))

I tried with jdk11, jdk16 with the same problem. Also tried to use asm 9.3 instead asm 9.2.
All works fine if I specify 8 in the maven compiler plugin.

I think there is something wrong with the String + operator and ASM but I cannot reproduce this problem with a simple test parser
Any clue?

Thanks regards,

[sirthias]

Thank you, @plamaiziere, for this bug report.
It'd be helpful if you could distill a minimal, stand-alone test case that demonstrates a problem in a reproducible form.
But even then I'm afraid that there is currently no one with the capacity to look into the codebase and identify + fix the problem. parboiled is now 12 years old and hasn't really been maintained for at least 8 years.
It's old and nobody really knows plus understands its internals anymore...

[plamaiziere]

@sirthias hello
I tried to reproduce the problem with a simple parser but it works fine and i can't reproduce it. It's hard to tell why.
I understand well that Partboiled is unmaintened, that's already nice to have a new version for jdk > 8
My issue was mostly for the record if someone else is seeing this pb.
Regards,