Re: [PATCH] getdate add a week when the wday is the same as the current one

[Jim Meyering]

Giuseppe Scrivano wrote:
> This patch includes all your suggestions and new tests for
> test-getdate.c.

Thanks for the quick test addition!
I want the summary line to start with "getdate: "
and do be "high-level descriptive" so I moved your
"add a week..." sentence into the body of the log.
Also, I kept the TAB-oriented indentation and made
Bruno's simplification (Thanks, Bruno!).

Regarding the test, I added a "const" and tweaked formatting
so the continued expression starts with "&&" rather than
leaving the operator at the end of the preceding line.
That is the prevailing and recommended style.

However, there is a problem.
With this change, today (a Friday), ./date -d fri
prints the date for a week from today.
Without the patch, it prints today's date.
That is a regression, and shows that we'll need
several more tests.

If you make further changes, please use the following
as a basis, so I don't have to change your spaces to TABs
again or to adjust the content or formatting of the commit log.


>From 664db25a03246f510793d74fce674b68f32d1dc3 Mon Sep 17 00:00:00 2001
From: Giuseppe Scrivano <address@hidden>
Date: Fri, 1 May 2009 09:23:20 +0200
Subject: [PATCH] getdate: correctly interpret "next monday" when run on a Monday
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

* lib/getdate.y (get_date): Correct the calculation of tm_mday so
that e.g., "next tues" (when run on a tuesday) results in a date
that is one week in the future, and not today's date.
I.e., add a week when the wday is the same as the current one.
Reported by Tom Broadhurst in http://savannah.gnu.org/bugs/?25406,
and earlier by Martin Bernreuther and Jan Minář.
* tests/test-getdate.c (main): Check that "next DAY" is always in
the future.
---
 lib/getdate.y        |    6 ++++--
 tests/test-getdate.c |   30 ++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/lib/getdate.y b/lib/getdate.y
index 877b264..48bf391 100644
--- a/lib/getdate.y
+++ b/lib/getdate.y
@@ -1,7 +1,7 @@
 %{
 /* Parse a string into an internal time stamp.

-   Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+   Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
    Free Software Foundation, Inc.

    This program is free software: you can redistribute it and/or modify
@@ -1435,7 +1435,9 @@ get_date (struct timespec *result, char const *p, struct 
timespec const *now)
       if (pc.days_seen && ! pc.dates_seen)
        {
          tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7
-                        + 7 * (pc.day_ordinal - (0 < pc.day_ordinal)));
+                        + 7 * (pc.day_ordinal
+                               - (0 < pc.day_ordinal
+                                  && tm.tm_wday != pc.day_number)));
          tm.tm_isdst = -1;
          Start = mktime (&tm);
          if (Start == (time_t) -1)
diff --git a/tests/test-getdate.c b/tests/test-getdate.c
index 7dfb09e..9cee073 100644
--- a/tests/test-getdate.c
+++ b/tests/test-getdate.c
@@ -48,6 +48,22 @@
 #define LOG(str, now, res) (void) 0
 #endif

+static const char* const day_table[] =
+{
+  "SUNDAY",
+  "MONDAY",
+  "TUESDAY",
+  "TUES",
+  "WEDNESDAY",
+  "WEDNES",
+  "THURSDAY",
+  "THUR",
+  "THURS",
+  "FRIDAY",
+  "SATURDAY",
+  NULL
+};
+
 int
 main (int argc, char **argv)
 {
@@ -55,6 +71,7 @@ main (int argc, char **argv)
   struct timespec result2;
   struct timespec now;
   const char *p;
+  int i;

   set_program_name (argv[0]);

@@ -211,5 +228,18 @@ main (int argc, char **argv)
   ASSERT (result.tv_sec == result2.tv_sec
          && result.tv_nsec == result2.tv_nsec);

+  /* Check that every 'next DAY' is in the future.  */
+  for (i = 0; day_table[i]; i++)
+    {
+      char tmp[32];
+      sprintf (tmp, "NEXT %s", day_table[i]);
+      now.tv_sec = 4711;
+      now.tv_nsec = 1267;
+      ASSERT (get_date (&result, tmp, &now));
+      LOG (tmp, now, result);
+      ASSERT (result.tv_sec > now.tv_sec
+             && result.tv_nsec == 0);
+    }
+
   return 0;
 }
--
1.6.3.rc3.212.g8c698