From hucka@eecs.umich.edu Thu Feb 8 12:19:15 EST 1996 Article: 18041 of news.software.nntp Path: news.math.psu.edu!news.iag.net!news.worldpath.net!news.cic.net!condor.ic.net!news2.acs.oakland.edu!jobone!newsxfer.itd.umich.edu!news.eecs.umich.edu!usenet From: hucka@eecs.umich.edu (Michael Hucka) Newsgroups: news.software.nntp,news.software.readers Subject: Re: TRN/INN Repeatedly asking about same "new" newsgroups Date: 07 Feb 1996 20:11:33 -0500 Organization: University of Michigan EECS, Ann Arbor, Mich., USA Lines: 152 Sender: hucka@hawk.eecs.umich.edu Distribution: inet Message-ID: <82g2cmsjsq.fsf@hawk.eecs.umich.edu> References: <4fbbqd$110f@lewis.cs.unc.edu> Reply-To: hucka@eecs.umich.edu NNTP-Posting-Host: hawk.eecs.umich.edu In-reply-to: taft@cs.unc.edu's message of 7 Feb 1996 18:15:25 -0500 X-Attribution: Mike Hucka To: taft@cs.unc.edu (Todd D. Taft) X-Newsreader: Gnus v5.1 Xref: news.math.psu.edu news.software.nntp:18041 news.software.readers:22491 >>>>> On 7 Feb 1996, taft@cs.unc.edu (Todd D. Taft) wrote: taft> Recently our news reader programs (primarily trn) have started taft> telling our users that new newsgroups have been created, and asking taft> users if they would like to subscribe to these certain newsgroups taft> every time that they start up the program. It will only ask about taft> newsgroups that are not listed in the user's .newsrc file, but it taft> won't ask about every newsgroup not listed in the .newsrc file. The taft> only pattern that I can detect is that the ones that users keep taft> getting prompted about have been newgrouped on our server relatively taft> recently. Our server used to allow users to list only the newsgroups taft> .... [rest deleted] .... This kind of sounds like the trn leap year bug. Attached is the patch posted last month: From: anne@alcor.concordia.ca ( Anne Bennett ) Subject: Re: trn-3.4.1 keeps asking about new groups! Date: 11 Jan 1996 20:44:37 GMT Newsgroups: news.software.readers,news.admin.misc,news.software.nntp Organization: Concordia University, Montreal, Canada Lines: 124 Message-ID: <4d3srl$qb1@newsflash.concordia.ca> References: <4cgtn4$npm@sidhe.hsc-sec.fr> <4clqq6$j5c@newsflash.concordia.ca> I wrote: > That patch is not correct [...] > A better patch is being > elaborated on the trn testers' mailing list. I can post it here when > it's done. 1) I was wrong; the patch was OK, at least until 2100. I re-append it here as the "simple patch". 2) A more correct but more complicated patch, appended here as "fancy patch", was submitted, which will work until 2400. Wayne Davison, author of trn, writes that he will go with the simple patch because the resulting calculation is faster, and he hopes no-one will still be using trn in the year 2100. :-) I am using the fancy patch at my site. Pick your own favourite; either will work. BTW, you should have no trouble applying these patches to strn-0.9.2, if that's what you're using, though the line numbers are for trn-3.6. Anne. -- Ms. Anne Bennett anne@alcor.concordia.ca (514) 848-7606 Computing Services, Concordia University, Montreal QC, Canada H3G 1M8 (Administrator for Concordia University mail relay and news transfer) ---------------------------------------------------------------------------- SIMPLE PATCH THAT WORKS UNTIL 2100 Submitted by Miquel van Smoorenburg , reposted to trn-test list by jml4@cus.cam.ac.uk (John Line)> ===== the patch (to nntp.c, line numbers are for trn 3.6) ------- nntp.c ------- *** /tmp/da005NK Thu Jan 1 00:00:00 1970 --- nntp.c Wed Jan 3 20:43:11 1996 *************** *** 319,326 **** for (month--; month; month--) day += maxdays[month]; ! ss = ((((year-1970) * 365 + (year-1968)/4 + day - 1) * 24L + hh) * 60 ! + mm) * 60 + ss; return ss; } --- 319,326 ---- for (month--; month; month--) day += maxdays[month]; ! ss = ((((year-1970) * 365 + (year-1969)/4 + day - 1) * 24L + hh) * 60 ! + mm) * 60 + ss; return ss; } ---------------------------------------------------------------------------- FANCY PATCH THAT WORKS UNTIL 2400 From: pdc@lunch.engr.sgi.com (Paul Close) Subject: Re: trn (3.6 & 4.0-test38) listing "new groups" that aren't new To: trn-test@trn.com (TRN mailing list) Date: Fri, 5 Jan 1996 16:43:27 -0800 (PST) Okay, here's my fix. This uses a proper leap year calculation, and should work for a very long time :-) --- trn-3.6/nntp.c Fri Nov 18 22:01:23 1994 +++ nntp.c.leap Fri Jan 5 16:38:33 1996 @@ -285,12 +285,13 @@ /* This is a 1-relative list */ static int maxdays[] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; +#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) time_t nntp_time() { char *s; - int year, month, day, hh, mm; + int year, month, day, hh, mm, y; time_t ss; nntp_command("XDATE" + (CompliantServer? 0 : 1)); @@ -306,11 +307,11 @@ s[4] = '\0'; year = atoi(s); - /* This simple algorithm will be valid until the year 2400 */ - if (year % 4) - maxdays[2] = 28; - else + if (isleap(year)) maxdays[2] = 29; + else + maxdays[2] = 28; + if (month < 1 || month > 12 || day < 1 || day > maxdays[month] || hh < 0 || hh > 23 || mm < 0 || mm > 59 || ss < 0 || ss > 59) @@ -319,8 +320,12 @@ for (month--; month; month--) day += maxdays[month]; - ss = ((((year-1970) * 365 + (year-1968)/4 + day - 1) * 24L + hh) * 60 - + mm) * 60 + ss; + for (y = 1970; y < year; y++) + if (isleap(y)) + day += 366; + else + day += 365; + ss += (((day - 1) * 24L + hh) * 60 + mm) * 60; return ss; } ---------------------------------------------------------------------------- -- Mike Hucka University of Michigan Artificial Intelligence Lab hucka@umich.edu (X.500) and EECS Departmental Computing Organization http://ai.eecs.umich.edu/people/hucka/ Ann Arbor, Michigan 48109, U.S.A.