[PATCH] posixtm: don't reject a time with "60" as the number of seconds

[Jim Meyering]

This patch is to make it so touch -t works with a time stamp
ending in ".60".  Without this change, "touch -t 200901010800.60 file"
would fail.  Note that the change below makes a recursive call to
posixtime.  That may not be the most efficient, but I suspect this
case is relatively unusual and I'd much prefer to have code that is
obviously correct than code that is optimized for a case that will
rarely arise.  If anyone can see a cleaner way, please speak up.

FYI, I ran the built-in tests by compiling like this:

    gcc -I/t -DTEST_POSIXTIME -g -O -Wall -W posixtm.c

and running the test like this:

    sed -n '/^BEGIN-DATA$/,/^END-DATA$/p' posixtm.c|grep -v DATA> in;
    TZ=UTC0 ./a.out < in |diff -u - in

Here's its output:

    --- -       2009-09-14 14:32:58.934253776 +0200
    +++ in      2009-09-14 14:32:58.930840392 +0200
    @@ -1,6 +1,6 @@
    -12131415.16     13   1260713716 Sun Dec 13 14:15:16 2009
    -12131415.16     13   1260713716 Sun Dec 13 14:15:16 2009
    -000001010000.00 13 -62167219200 Sat Jan  1 00:00:00 0
    +12131415.16     13   1039788916 Fri Dec 13 14:15:16 2002
    +12131415.16     13   1039788916 Fri Dec 13 14:15:16 2002
    +000001010000.00 13 -62167132800 Sun Jan  1 00:00:00 0000
     190112132045.52 13  -2147483648 Fri Dec 13 20:45:52 1901
     190112132045.53 13  -2147483647 Fri Dec 13 20:45:53 1901
     190112132046.52 13  -2147483588 Fri Dec 13 20:46:52 1901

Note that the first two differences are to be expected.
Those tests pass only if 2002 is the current year.
However, I don't know about the difference in the 3rd line.
Note the s/Sat/Sun/ change.  The new number of seconds is 86400
larger than the old one; that's exactly one day's worth of seconds,
and hence in line with the Sat/Sun change.

I don't yet know if this change is a problem in mktime or due
to some intervening fix.

First, I'll commit this.

Then I'll write a proper test module.

Then, maybe, I'll worry about the DoW of Jan 1, year-zero ;-)

>From 6c9f1e88ada406b65f6b10098b8c9e60c973e614 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sun, 13 Sep 2009 00:35:49 +0200
Subject: [PATCH] posixtm: don't reject a time with "60" as the number of seconds

* lib/posixtm.c (posixtime): The code to reject invalid dates would
also reject a time specified with the .60 suffix, whereas POSIX allows
that, in order to accommodate leap seconds.  Don't reject that.
(main): Adjust tests accordingly.
* modules/posixtm (Depends-on): Add stpcpy.
---
 ChangeLog       |   10 ++++++++++
 lib/posixtm.c   |   23 +++++++++++++++++++----
 modules/posixtm |    1 +
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 94bac83..dc32b4d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2009-09-13  Jim Meyering  <address@hidden>
+
+       posixtm: don't reject a time that specify "60" as the number of seconds
+       * lib/posixtm.c (posixtime): The code to reject invalid dates
+       would also reject a time specified with the .60 suffix.
+       But POSIX allows that, in order to accommodate leap seconds.
+       So don't reject it.
+       (main): Adjust tests accordingly.
+       * modules/posixtm (Depends-on): Add stpcpy.
+
 2009-09-11  Jim Meyering  <address@hidden>

        announce-gen: include [$release_type] in emitted Subject:
diff --git a/lib/posixtm.c b/lib/posixtm.c
index 4d044a3..0a1e779 100644
--- a/lib/posixtm.c
+++ b/lib/posixtm.c
@@ -1,7 +1,7 @@
 /* Parse dates for touch and date.

    Copyright (C) 1989, 1990, 1991, 1998, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007 Free Software Foundation Inc.
+   2005, 2006, 2007, 2009 Free Software Foundation Inc.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -207,14 +207,29 @@ posixtime (time_t *p, const char *s, unsigned int 
syntax_bits)
        return false;
     }

-  /* Reject dates like "September 31" and times like "25:61".  */
+  /* Reject dates like "September 31" and times like "25:61".
+     Do not reject times that specify "60" as the number of seconds.  */
   if ((tm0.tm_year ^ tm->tm_year)
       | (tm0.tm_mon ^ tm->tm_mon)
       | (tm0.tm_mday ^ tm->tm_mday)
       | (tm0.tm_hour ^ tm->tm_hour)
       | (tm0.tm_min ^ tm->tm_min)
       | (tm0.tm_sec ^ tm->tm_sec))
-    return false;
+    {
+      /* Any mismatch without 60 in the tm_sec field is invalid.  */
+      if (tm0.tm_sec != 60)
+        return false;
+
+      {
+        /* Allow times like 01:35:60 or 23:59:60.  */
+        time_t dummy;
+        char buf[16];
+        char *b = stpcpy (buf, s);
+        strcpy (b - 2, "59");
+        if (!posixtime (&dummy, buf, syntax_bits))
+          return false;
+      }
+    }

   *p = t;
   return true;
@@ -251,13 +266,13 @@ BEGIN-DATA
 197001010000.00 13            0 Thu Jan  1 00:00:00 1970
 197001010000.01 13            1 Thu Jan  1 00:00:01 1970
 197001010001.00 13           60 Thu Jan  1 00:01:00 1970
+197001010000.60 13           60 Thu Jan  1 00:01:00 1970
 197001010100.00 13         3600 Thu Jan  1 01:00:00 1970
 197001020000.00 13        86400 Fri Jan  2 00:00:00 1970
 197002010000.00 13      2678400 Sun Feb  1 00:00:00 1970
 197101010000.00 13     31536000 Fri Jan  1 00:00:00 1971
 197001000000.00 13            * *
 197000010000.00 13            * *
-197001010000.60 13            * *
 197001010060.00 13            * *
 197001012400.00 13            * *
 197001320000.00 13            * *
diff --git a/modules/posixtm b/modules/posixtm
index 06af4c8..425c175 100644
--- a/modules/posixtm
+++ b/modules/posixtm
@@ -9,6 +9,7 @@ m4/posixtm.m4
 Depends-on:
 mktime
 stdbool
+stpcpy

 configure.ac:
 gl_POSIXTM
--
1.6.5.rc1.171.g3f463