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Postings from November 2016
On Mon, 07 Nov 2016 22:14:43 GMT, demerphq wrote:
> On 7 November 2016 at 17:29, James E Keenan via RT
> <perlbug-followup@perl.org> wrote:
> > On Mon, 07 Nov 2016 13:47:55 GMT, jkeenan wrote:
> >>
> >> The question is: What is it about this the pattern:
> >>
> >> #####
> >> /([^\S\x{202f}\x{00a0}]+)|(\p{InFullwidth})|((?:[^\s\p{InFullwidth}]|[\x{202f}\x{00a0}])+)/
> >> #####
> >>
> >> ... that (a) as of commit C<a5540cf> but not previously; and (b) in
> >> the context of this test suite but not in isolation, perceives
> >> something to be a read-only value not subject to modification?
> >
> > My next brainstorm: Add "use re 'debug';" to sub add_text() in
> > tp/Texinfo/Convert/ParagraphNonXS.pm.
> >
> > When I did so and ran the debugging program found in one of my
> > previous attachments, I got this output:
> >
> > #####
> > Texinfo::Convert::ParagraphNonXS::add_text(../../tp/Texinfo/Convert/ParagraphNonXS.pm:329):
> > 329: my @segments = split
> > 330:
> > /([^\S\x{202f}\x{00a0}]+)|(\p{InFullwidth})|((?:[^\s\p{InFullwidth}]|[\x{202f}\x{00a0}])+)/,
> > 331: $text;
> > DB<6> n
> > Matching REx
> > "([^\S\x{202f}\x{00a0}]+)|(\p{InFullwidth})|((?:[^\s\p{InFull"...
> > against "This is "
> > 0 <> <This is > | 0| 1:BRANCH(18)
> > 0 <> <This is > | 1| 2:OPEN1(4)
> > 0 <> <This is > | 1| 4:PLUS(16)
> > | 1| ANYOF[\t\n\x0B\f\r \x85][1680
> > | 2000-200A 2028-2029 205F 3000] can
> > | match 0 times out of 2147483647...
> > | 1| failed...
> > 0 <> <This is > | 0| 18:BRANCH(34)
> > 0 <> <This is > | 1| 19:OPEN2(21)
> > 0 <> <This is > | 1|
> > 21:ANYOF[+utf8::Texinfo::Convert::ParagraphNonXS::InFullwidth](32)
> > | 1| failed...
> > 0 <> <This is > | 0| 34:BRANCH(68)
> > 0 <> <This is > | 1| 35:OPEN3(37)
> > 0 <> <This is > | 1| 37:CURLYM[0]{1,INFTY}(66)
> > 0 <> <This is > | 2| 39:BRANCH(51)
> > 0 <> <This is > | 3| 40:ANYOF[^\t\n\x0B\f\r
> > \x85\xA0{+utf8::Texinfo::Convert::ParagraphNonXS::InFullwidth}1680
> > 2000-200A 2028-2029 202F 205F 3000](64)
> > Modification of a read-only value attempted at
> > ../../tp/Texinfo/Convert/ParagraphNonXS.pm line 329.
> > at ../../tp/Texinfo/Convert/ParagraphNonXS.pm line 329.
> > Texinfo::Convert::ParagraphNonXS::add_text(Texinfo::Convert::ParagraphNonXS=HASH(0x35ba938),
> > "This is ") called at ../../tp/Texinfo/Convert/Info.pm line 308
> > Texinfo::Convert::Info::_info_header(Texinfo::Convert::Info=HASH(0x35b3038))
> > called at ../../tp/Texinfo/Convert/Info.pm line 81
> > Texinfo::Convert::Info::output(Texinfo::Convert::Info=HASH(0x35b3038),
> > HASH(0x35ab7c0)) called at ../texi2any.pl line 1348
> > panic: POPSTACK
> > Debugged program terminated.
> > #####
> >
> > Since I have never previously used the regex debugger, I have no idea
> > if there are any clues to a solution in that output.
> >
> > Thoughts?
>
> It looks like the pattern
>
> [^\s\p{InFullwidth}]
>
> causes this.
>
> Yves
Very likely. When, at an earlier stage of debugging, I removed the two parts of the pattern that contained '\p{InFullwidth}', the panic disappeared.
However, that pattern was not panicking up until commit a5540cf. And, even with a5540cf and commits thereafter (e.g., HEAD of blead), I can write a very simple perl program that has that pattern and not get a panic.
It's something about the interaction of commit a5540cf, that pattern, and the code in texinfo that is the problem.
Thanks for taking a look at this.
--
James E Keenan (jkeenan@cpan.org)
---
via perlbug: queue: perl5 status: open
https://rt.perl.org/Ticket/Display.html?id=130010
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