Moved some generically useful date/time handling functions to mutil.c,

fixed problems with portability of timezone information in struct tm, and
moved created a new structure to hold timezone information, since struct
tm doesn't do so reliably.

+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Library Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifndef _MAILUTILS_MUTIL_H
+#define _MAILUTILS_MUTIL_H
+
+/*
+   Collection of useful utility routines that are worth sharing,
+   but don't have a natural home somewhere else.
+*/
+
+#include <time.h>
+
+#ifndef __P
+# ifdef __STDC__
+#  define __P(args) args
+# else
+#  define __P(args) ()
+# endif
+#endif /*__P */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct mu_timezone
+{
+  int utc_offset;
+    /* Seconds east of UTC. */
+
+  const char *tz_name;
+    /* Nickname for this timezone, if known. It is always considered
+     * to be a pointer to static string, so will never be freed. */
+};
+
+typedef struct mu_timezone mu_timezone;
+
+extern int mu_parse_imap_date_time __P ((const char **p, struct tm * tm,
+					 mu_timezone * tz));
+extern int mu_parse_ctime_date_time __P ((const char **p, struct tm * tm,
+					 mu_timezone * tz));
+
+extern time_t mu_utc_offset __P ((void));
+extern time_t mu_tm2time __P ((struct tm * timeptr, mu_timezone * tz));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _MAILUTILS_MUTIL_H */
+

@@ -44,7 +44,7 @@ memory_stream.c \
 mime.c \
 misc.c \
 monitor.c \
-mu_mktime.c \
+mutil.c \
 muerror.c \
 observer.c \
 parse822.c \

@@ -30,12 +30,11 @@
 
 #include <mailutils/address.h>
 #include <mailutils/error.h>
+#include <mailutils/mutil.h>
 #include <mailbox0.h>
 #include <registrar0.h>
 #include <imap0.h>
 
-extern time_t mu_mktime __P((struct tm *timeptr, int tz));
-
 /* Functions to overload the mailbox_t API.  */
 static void mailbox_imap_destroy __P ((mailbox_t));
 static int mailbox_imap_open     __P ((mailbox_t, int));
@@ -91,13 +90,6 @@ static int imap_get_message0     __P ((msg_imap_t, message_t *));
 static int message_operation     __P ((f_imap_t, msg_imap_t, char *, size_t, size_t *));
 static void free_subparts        __P ((msg_imap_t));
 
-static const char *MONTHS[] =
-{
-  "Jan", "Feb", "Mar", "Apr", "May", "Jun",
-  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
-};
-
-
 /* Initialize the concrete object mailbox_t by overloading the function of the
    structure.  */
 int
@@ -1232,67 +1224,6 @@ imap_envelope_sender (envelope_t envelope, char *buffer, size_t buflen,
   return status;
 }
 
-int
-imap_parse_date_time (const char **p, struct tm *tm, int *tz)
-{
-  int year, mon, day, hour, min, sec;
-  char zone[6] = "+0000";	/* ( "+" / "-" ) hhmm */
-  char month[5] = "";
-  int hh = 0;
-  int mm = 0;
-  int sign = 1;
-  int scanned = 0, scanned3;
-  int i;
-
-  day = mon = year = hour = min = sec = 0;
-
-  memset (tm, 0, sizeof (*tm));
-
-  switch (sscanf (*p,
-		  "%2d-%3s-%4d%n %2d:%2d:%2d %5s%n",
-		  &day, month, &year, &scanned3, &hour, &min, &sec, zone,
-		  &scanned))
-    {
-    case 3:
-      scanned = scanned3;
-      break;
-    case 7:
-      break;
-    default:
-      return -1;
-    }
-
-  tm->tm_sec = sec;
-  tm->tm_min = min;
-  tm->tm_hour = hour;
-  tm->tm_mday = day;
-
-  for (i = 0; i < 12; i++)
-    {
-      if (strncasecmp (month, MONTHS[i], 3) == 0)
-	{
-	  mon = i;
-	  break;
-	}
-    }
-  tm->tm_mon = mon;
-  tm->tm_year = (year > 1900) ? year - 1900 : year;
-  tm->tm_yday = 0;		/* unknown. */
-  tm->tm_wday = 0;		/* unknown. */
-  tm->tm_isdst = -1;		/* unknown. */
-
-  hh = (zone[1] - '0') * 10 + (zone[2] - '0');
-  mm = (zone[3] - '0') * 10 + (zone[4] - '0');
-  sign = (zone[0] == '-') ? -1 : +1;
-
-  if (tz)
-    *tz = sign * (hh * 60 * 60 + mm * 60);
-
-  *p += scanned;
-
-  return 0;
-}
-
 static int
 imap_envelope_date (envelope_t envelope, char *buffer, size_t buflen,
 		    size_t *plen)
@@ -1302,7 +1233,7 @@ imap_envelope_date (envelope_t envelope, char *buffer, size_t buflen,
   m_imap_t m_imap = msg_imap->m_imap;
   f_imap_t f_imap = m_imap->f_imap;
   struct tm tm;
-  int tz;
+  mu_timezone tz;
   time_t now;
   char datebuf[] = "mm-dd-yyyy hh:mm:ss +0000";
   const char* date = datebuf;
@@ -1326,10 +1257,10 @@ imap_envelope_date (envelope_t envelope, char *buffer, size_t buflen,
   if (status != 0)
     return status;
 
-  if (imap_parse_date_time(datep, &tm, &tz) != 0)
+  if (mu_parse_imap_date_time(datep, &tm, &tz) != 0)
     now = (time_t)-1;
   else
-    now = mu_mktime (&tm, tz);
+    now = mu_tm2time (&tm, &tz);
 
   /* if the time was unparseable, or mktime() didn't like what we
      parsed, use the calendar time. */

+/* Copyright (C) 2001 Free Software Foundation, Inc.
+   A wrapper for mktime function allowing to specify the timezone.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+#include <time.h>
+
+#include <mailutils/mutil.h>
+/* Convert struct tm into time_t, taking into account timezone offset.
+ 
+ mktime() always treats tm as if it was localtime, so convert it
+ to UTC, then adjust by the tm's real timezone, if it is known.
+*/
+time_t
+mu_tm2time (struct tm *timeptr, mu_timezone* tz)
+{
+  int offset = tz ? tz->utc_offset : 0;
+  
+  return mktime(timeptr) - mu_utc_offset() + offset;
+}
+
+/* Convert time 0 at UTC to our localtime, that tells us the offset
+   of our current timezone from UTC. */
+time_t mu_utc_offset(void)
+{
+  time_t t = 0;
+  struct tm* tm = gmtime(&t);
+
+  return mktime(tm);
+}
+
+static const char *months[] =
+{
+  "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec", NULL
+};
+
+static const char *wdays[] =
+{
+  "Mon", "Teu", "Wed", "Thr", "Fri", "Sat", "Sun", NULL
+};
+
+int
+mu_parse_imap_date_time (const char **p, struct tm *tm, mu_timezone *tz)
+{
+  int year, mon, day, hour, min, sec;
+  char zone[6] = "+0000";	/* ( "+" / "-" ) hhmm */
+  char month[5] = "";
+  int hh = 0;
+  int mm = 0;
+  int sign = 1;
+  int scanned = 0, scanned3;
+  int i;
+  int tzoffset;
+
+  day = mon = year = hour = min = sec = 0;
+
+  memset (tm, 0, sizeof (*tm));
+
+  switch (sscanf (*p,
+		  "%2d-%3s-%4d%n %2d:%2d:%2d %5s%n",
+		  &day, month, &year, &scanned3, &hour, &min, &sec, zone,
+		  &scanned))
+    {
+    case 3:
+      scanned = scanned3;
+      break;
+    case 7:
+      break;
+    default:
+      return -1;
+    }
+
+  tm->tm_sec = sec;
+  tm->tm_min = min;
+  tm->tm_hour = hour;
+  tm->tm_mday = day;
+
+  for (i = 0; i < 12; i++)
+    {
+      if (strncasecmp (month, months[i], 3) == 0)
+	{
+	  mon = i;
+	  break;
+	}
+    }
+  tm->tm_mon = mon;
+  tm->tm_year = (year > 1900) ? year - 1900 : year;
+  tm->tm_yday = 0;		/* unknown. */
+  tm->tm_wday = 0;		/* unknown. */
+#if HAVE_TM_ISDST
+  tm->tm_isdst = -1;		/* unknown. */
+#endif
+
+  hh = (zone[1] - '0') * 10 + (zone[2] - '0');
+  mm = (zone[3] - '0') * 10 + (zone[4] - '0');
+  sign = (zone[0] == '-') ? -1 : +1;
+  tzoffset = sign * (hh * 60 * 60 + mm * 60);
+
+#if HAVE_TM_GMTOFFSET
+  tm->tm_gmtoffset = tzoffset;
+#endif
+
+  if (tz)
+    {
+      tz->utc_offset = tzoffset;
+      tz->tz_name = NULL;
+    }
+
+  *p += scanned;
+
+  return 0;
+}
+
+/* "ctime" format is: Thu Jul 01 15:58:27 1999, with no trailing \n.  */
+int
+mu_parse_ctime_date_time (const char **p, struct tm *tm, mu_timezone * tz)
+{
+  int wday = 0;
+  int year = 0;
+  int mon = 0;
+  int day = 0;
+  int hour = 0;
+  int min = 0;
+  int sec = 0;
+  int n = 0;
+  int i;
+  char weekday[5] = "";
+  char month[5] = "";
+
+  if (sscanf (*p, "%3s %3s %2d %2d:%2d:%2d %d%n\n",
+	weekday, month, &day, &hour, &min, &sec, &year, &n) != 7)
+    return -1;
+
+  *p += n;
+
+  for (i = 0; i < 7; i++)
+    {
+      if (strncasecmp (weekday, wdays[i], 3) == 0)
+	{
+	  wday = i;
+	  break;
+	}
+    }
+
+  for (i = 0; i < 12; i++)
+    {
+      if (strncasecmp (month, months[i], 3) == 0)
+	{
+	  mon = i;
+	  break;
+	}
+    }
+
+  if (tm)
+    {
+      memset (tm, 0, sizeof (struct tm));
+
+      tm->tm_sec = sec;
+      tm->tm_min = min;
+      tm->tm_hour = hour;
+      tm->tm_mday = day;
+      tm->tm_wday = wday;
+      tm->tm_mon = mon;
+      tm->tm_year = (year > 1900) ? year - 1900 : year;
+#ifdef HAVE_TM_ISDST
+      tm->tm_isdst = -1;	/* unknown. */
+#endif
+    }
+
+  /* ctime has no timezone information, set tz to UTC if they ask. */
+  if (tz)
+    memset (tz, 0, sizeof (struct mu_timezone));
+
+  return 0;
+}
+
+

@@ -1431,7 +1431,7 @@ struct tm
 };
 #endif
 
-int parse822_date_time(const char** p, const char* e, struct tm* tm)
+int parse822_date_time(const char** p, const char* e, struct tm* tm, struct mu_timezone* tz)
 {
   /* date-time = [ day "," ] date time */
 
@@ -1448,7 +1448,7 @@ int parse822_date_time(const char** p, const char* e, struct tm* tm)
   int min = 0;
   int sec = 0;
 
-  int tz = 0;
+  int tzoffset = 0;
   const char* tzname = 0;
 
   if((rc = parse822_day(p, e, &wday))) {
@@ -1468,7 +1468,7 @@ int parse822_date_time(const char** p, const char* e, struct tm* tm)
     *p = save;
     return rc;
   }
-  if((rc = parse822_time(p, e, &hour, &min, &sec, &tz, &tzname))) {
+  if((rc = parse822_time(p, e, &hour, &min, &sec, &tzoffset, &tzname))) {
     *p = save;
     return rc;
   }
@@ -1486,9 +1486,21 @@ int parse822_date_time(const char** p, const char* e, struct tm* tm)
     tm->tm_min  = min;
     tm->tm_sec  = sec;
 
+#ifdef HAVE_TM_ISDST
     tm->tm_isdst = -1; /* unknown whether it's dst or not */
-    tm->tm_gmtoff = tz;
+#endif
+#ifdef HAVE_TM_GMTOFF
+    tm->tm_gmtoff = tzoffset;
+#endif
+#ifdef HAVE_TM_ZONE
     tm->tm_zone = tzname;
+#endif
+  }
+
+  if(tz)
+  {
+    tz->utc_offset = tzoffset;
+    tz->tz_name = tzname;
   }
 
   return EOK;