From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/88011 Path: news.gmane.org!not-for-mail From: Hans Hagen Newsgroups: gmane.comp.tex.context Subject: Re: underbraces get progressively more misaligned (w/ minimal example) Date: Sat, 05 Jul 2014 02:30:36 +0200 Message-ID: <53B7472C.90607@wxs.nl> References: <87d2dsnhui.fsf@approx.mit.edu> <877g40nhcl.fsf@approx.mit.edu> <87k37u7m4e.fsf@approx.mit.edu> <66D45391-7643-4952-BF98-7439FCEC856B@gmail.com> <87a98q40ks.fsf@approx.mit.edu> <53B5D497.1040108@wxs.nl> <871tu23w7e.fsf@approx.mit.edu> <53B5DE6B.8040104@wxs.nl> <87simh31s7.fsf@approx.mit.edu> Reply-To: mailing list for ConTeXt users NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1404520269 5569 80.91.229.3 (5 Jul 2014 00:31:09 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 5 Jul 2014 00:31:09 +0000 (UTC) To: Sanjoy Mahajan , mailing list for ConTeXt users Original-X-From: ntg-context-bounces@ntg.nl Sat Jul 05 02:31:02 2014 Return-path: Envelope-to: gctc-ntg-context-518@m.gmane.org Original-Received: from balder.ntg.nl ([5.39.185.229]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1X3Dsc-00052x-L3 for gctc-ntg-context-518@m.gmane.org; Sat, 05 Jul 2014 02:31:02 +0200 Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id E1EAA10221 for ; Sat, 5 Jul 2014 02:31:01 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (balder.ntg.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id ooXaP2vQs-Sr for ; Sat, 5 Jul 2014 02:31:01 +0200 (CEST) Original-Received: from balder.ntg.nl (localhost [IPv6:::1]) by balder.ntg.nl (Postfix) with ESMTP id D0B5A10223 for ; Sat, 5 Jul 2014 02:30:53 +0200 (CEST) Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 0818B101E8 for ; Sat, 5 Jul 2014 02:30:50 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (balder.ntg.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id RZcW5lAXj7gr for ; Sat, 5 Jul 2014 02:30:44 +0200 (CEST) Original-Received: from filter3-til.mf.surf.net (filter3-til.mf.surf.net [194.171.167.219]) by balder.ntg.nl (Postfix) with ESMTP id B298A101E7 for ; Sat, 5 Jul 2014 02:30:44 +0200 (CEST) Original-Received: from smtp.ziggozakelijk.nl (D57D1DA2.static.ziggozakelijk.nl [213.125.29.162]) by filter3-til.mf.surf.net (8.14.3/8.14.3/Debian-9.4) with ESMTP id s650UcMo013328 for ; Sat, 5 Jul 2014 02:30:44 +0200 X-Default-Received-SPF: pass (skip=loggedin (res=PASS)) x-ip-name=10.100.1.104; Original-Received: from [10.100.1.104] (unverified [10.100.1.104]) by pragma-net.nl (SurgeMail 6.5a2) with ESMTP id 9489-1713362 for multiple; Sat, 05 Jul 2014 02:30:36 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 In-Reply-To: <87simh31s7.fsf@approx.mit.edu> X-Authenticated-User: hagen@controller-9 X-Bayes-Prob: 0.0001 (Score 0, tokens from: ntg-context@ntg.nl, base:default, @@RPTN) X-CanIt-Geo: ip=213.125.29.162; country=NL; region=Provincie Overijssel; city=Zwolle; latitude=52.5058; longitude=6.0858; http://maps.google.com/maps?q=52.5058,6.0858&z=6 X-CanItPRO-Stream: uu:ntg-context@ntg.nl (inherits from uu:default, base:default) X-Canit-Stats-ID: 06MmouCou - d0f5764820f4 - 20140705 (trained as not-spam) X-Scanned-By: CanIt (www . roaringpenguin . com) on 194.171.167.219 X-BeenThere: ntg-context@ntg.nl X-Mailman-Version: 2.1.14 Precedence: list List-Id: mailing list for ConTeXt users List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ntg-context-bounces@ntg.nl Original-Sender: ntg-context-bounces@ntg.nl Xref: news.gmane.org gmane.comp.tex.context:88011 Archived-At: On 7/4/2014 11:34 AM, Sanjoy Mahajan wrote: > Wolfgang Schuster writes: > >> It does also depend on the width of the text because when I use 48pt >> in the example below the height of the brace is always the same but >> with 49pt the height increases after the first page. > > An interesting bug. That's also consistent with my experiments, in which > > \underbrace{\hbox{yyyy yyyy}}_{\rho} > > triggers the problem, but > > \underbrace{\hbox{yyyy}}_{\rho} > > does not. Hi Sanjoy, After a day of testing, tracing, wondering etc Luigi and I figured out what was the problem it tooks us lots of debug prints -). Indeed there is a bug in luatex. An extensible is made up of a sequence char skip 0pt- xpt char skip 0pt- xpt char skip 0pt- xpt char And the code that determines the height/depth took the dimensions of skips into the equation while in fact glue has no such dimensions (leaders that are a special kind of glue have dimensions). Not the first place one looks for such an issue. Probably a side effect of copying a function and patching part. So, some random value (not entirely random as it depends on what mem area the glue node is allocated from and that is kind of stable in a run) was added which results in the effects you noticed. Because it is stable within a run (same successive errors) it doesn't result in oscillating (too many runs due to differences in results) and this is probably why it went unnoticed so long. Interesting. (Normally the pseudo random ht/dp were small.) So, once this fix moves upstream you can check your suspicious cases. Luigi will push it in our experimental branch and I suppose that Taco will then push it into trunk and after that you can compile or wait till the garden carries it. Thanks for noticing! Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com | www.pragma-pod.nl ----------------------------------------------------------------- ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________