# [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch 6 messages from 2007-06-06 to 2007-06-07. Participants: Johannes Sixt, Junio C Hamano, Sam Vilain, Johannes Schindelin. Thread: https://gitlist.dev/t/8465 ## Johannes Sixt, 2007-06-06 08:11 Subject: [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch Message-ID: <11811175153355-git-send-email-johannes.sixt@telecom.at> URL: https://gitlist.dev/e/11811175153355-git-send-email-johannes.sixt%40telecom.at ``` Tests with git-filter-branch on a repository that was converted from CVS and that has commits reaching back to 1999 revealed that it is necessary to parse dates before 2000/01/01 when they are specified as seconds since 1970/01/01. There is now still a limit, 100000000, which is 1973/03/03 09:46:40 UTC, in order to allow that dates are represented as 8 digits. Signed-off-by: Johannes Sixt --- date.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/date.c b/date.c index a9b59a2..4690371 100644 --- a/date.c +++ b/date.c @@ -414,9 +414,11 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt num = strtoul(date, &end, 10); /* - * Seconds since 1970? We trigger on that for anything after Jan 1, 2000 + * Seconds since 1970? We trigger on that for any numbers with + * more than 8 digits. This is because we don't want to rule out + * numbers like 20070606 as a YYYYMMDD date. */ - if (num > 946684800) { + if (num >= 100000000) { time_t time = num; if (gmtime_r(&time, tm)) { *tm_gmt = 1; -- 1.5.2.1.120.gd732 ``` ## Junio C Hamano, 2007-06-06 08:29 Subject: Re: [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch Message-ID: <7vtztl5vvb.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vtztl5vvb.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <11811175153355-git-send-email-johannes.sixt@telecom.at> ``` I vaguely recall hitting the same issue soon after date.c was done, and sending in a patch in the same spirit but with different implementation (I essentially duplicated that "seconds since epoch" without any cutoff as the last ditch fallback) long time ago (this was before I took git over; the patch was rejected). It almost makes me wonder if it is better to introduce a special syntax to denote "seconds since epoch plus timezone offset" for our Porcelain use, instead of keeping this arbitrary cut-off date which nobody can agree on and which forces us to roll back from time to time. For one thing, such a syntax would allow us to talk about a timestamp before the epoch. Perhaps "epoch" [-+] [0-9]+ " " [-+][0-9][0-9][0-9][0-9] ? ``` ## Johannes Sixt, 2007-06-06 10:42 Subject: Re: [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch Message-ID: <46668FAD.73D1B73F@eudaptics.com> URL: https://gitlist.dev/e/46668FAD.73D1B73F%40eudaptics.com In-Reply-To: <7vtztl5vvb.fsf@assigned-by-dhcp.cox.net> ``` Junio C Hamano wrote: > > I vaguely recall hitting the same issue soon after date.c was > done, and sending in a patch in the same spirit but with > different implementation (I essentially duplicated that "seconds > since epoch" without any cutoff as the last ditch fallback) long > time ago (this was before I took git over; the patch was rejected). > > It almost makes me wonder if it is better to introduce a special > syntax to denote "seconds since epoch plus timezone offset" for > our Porcelain use, instead of keeping this arbitrary cut-off > date which nobody can agree on and which forces us to roll back > from time to time. For one thing, such a syntax would allow us > to talk about a timestamp before the epoch. > > Perhaps > > "epoch" [-+] [0-9]+ " " [-+][0-9][0-9][0-9][0-9] > > ? OTOH, the previous limit 2000/01/01 was completely arbitrary, while the new limit 100000000secs has some justification: Numbers with fewer digits could be mistaken as dates. -- Hannes ``` ## Sam Vilain, 2007-06-07 05:09 Subject: Re: [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch Message-ID: <46679320.6000309@vilain.net> URL: https://gitlist.dev/e/46679320.6000309%40vilain.net In-Reply-To: <7vtztl5vvb.fsf@assigned-by-dhcp.cox.net> ``` Junio C Hamano wrote: > I vaguely recall hitting the same issue soon after date.c was > done, and sending in a patch in the same spirit but with > different implementation (I essentially duplicated that "seconds > since epoch" without any cutoff as the last ditch fallback) long > time ago (this was before I took git over; the patch was rejected). > > It almost makes me wonder if it is better to introduce a special > syntax to denote "seconds since epoch plus timezone offset" for > our Porcelain use, instead of keeping this arbitrary cut-off > date which nobody can agree on and which forces us to roll back > from time to time. For one thing, such a syntax would allow us > to talk about a timestamp before the epoch. > > Perhaps > > "epoch" [-+] [0-9]+ " " [-+][0-9][0-9][0-9][0-9] Probably a good idea, though it would break cg-admin-rewritehist. I had to make a similar change when working with the Perl history. Perhaps allow both? There is a 10 digit ISO forms (YYYYMMDDHH) and a 9 digit form (YYYYDDDHH), but these are very rare :) Sam. ``` ## Junio C Hamano, 2007-06-07 05:29 Subject: Re: [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch Message-ID: <7vbqfsqqmq.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vbqfsqqmq.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <46679320.6000309@vilain.net> ``` Sam Vilain writes: >> Perhaps >> >> "epoch" [-+] [0-9]+ " " [-+][0-9][0-9][0-9][0-9] > > Probably a good idea, though it would break cg-admin-rewritehist. I was saying "additionally allow that to express timestamp even before the epoch", and existing cg-admin-rewritehist does not feed such a string, so I do not know how the additionally allowed format could break it. Maybe I am missing something? In any case, "timestamps after March 1973" patch from j6t is a good change independent from the above one. ``` ## Johannes Schindelin, 2007-06-07 05:30 Subject: Re: [PATCH] Accept dates before 2000/01/01 when specified as seconds since the epoch Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0706070629180.4046%40racer.site In-Reply-To: <46679320.6000309@vilain.net> ``` Hi, On Thu, 7 Jun 2007, Sam Vilain wrote: > Junio C Hamano wrote: > > I vaguely recall hitting the same issue soon after date.c was > > done, and sending in a patch in the same spirit but with > > different implementation (I essentially duplicated that "seconds > > since epoch" without any cutoff as the last ditch fallback) long > > time ago (this was before I took git over; the patch was rejected). > > > > It almost makes me wonder if it is better to introduce a special > > syntax to denote "seconds since epoch plus timezone offset" for > > our Porcelain use, instead of keeping this arbitrary cut-off > > date which nobody can agree on and which forces us to roll back > > from time to time. For one thing, such a syntax would allow us > > to talk about a timestamp before the epoch. > > > > Perhaps > > > > "epoch" [-+] [0-9]+ " " [-+][0-9][0-9][0-9][0-9] > > Probably a good idea, though it would break cg-admin-rewritehist. FWIW I don't think we have to care that much about cg-admin-rewritehist, since it lives on as git-filter-branch, and we can adapt it as we go. Ciao, Dscho ```