mboxrb: Keep timestamps in normalized form

* include/mailutils/datetime.h (mu_timezone_offset): New proto.
* libmailutils/datetime/scantime.c: New conversion: %Z (timezone
abbreviation).
* libmailutils/datetime/parsedate.y (mu_timezone_offset): New function.
Returns time offset in seconds corresponding to the given timezone
abbreviation.

* include/mailutils/sys/mboxrb.h (mu_mboxrb_hdr): Remove unneeded
enum.
(mu_mboxrb_message): Remove env_date_start,
New member "date" holds the string representation of the envelope
timestamp in normalized form - ctime(3), UTC.
* libproto/mbox/mboxrb.c (scan_message_finalize): New function.
(scan_message_begin): New function.  When initializing the
message, timestamps in obsolete forms are converted to normalized
representation.
(mboxrb_rescan_unlocked): Use scan_message_finalize and
scan_message_begin.
* libproto/mbox/message.c (mboxrb_envelope_date): Get normalized
timestamp from the date member,
* libproto/mbox/tests/env.at: Reflect the above changes.

2 files changed, 39 insertions, 1 deletions

diff --git a/libmailutils/datetime/parsedate.y b/libmailutils/datetime/parsedate.y
index 977713001..372cdb2eb 100644
--- a/libmailutils/datetime/parsedate.y
+++ b/libmailutils/datetime/parsedate.y
@@ -1209,6 +1209,20 @@ mu_parse_date (const char *p, time_t *rettime, const time_t *now)
   return mu_parse_date_dtl (p, now, rettime, NULL, NULL, NULL);
 }
 
+int
+mu_timezone_offset (const char *buf, int *off)
+{
+  SYMBOL const *tp;
+  
+  for (tp = tz_tab; tp->name; tp++)
+    if (mu_c_strcasecmp (buf, tp->name) == 0)
+      {
+	*off = - tp->value * 60;
+	return 0;
+      }
+  return -1;
+}
+
 #ifdef STANDALONE
 int
 main (int argc, char *argv[])
diff --git a/libmailutils/datetime/scantime.c b/libmailutils/datetime/scantime.c
index 0b118b765..8e19a803b 100644
--- a/libmailutils/datetime/scantime.c
+++ b/libmailutils/datetime/scantime.c
@@ -538,7 +538,31 @@ mu_scan_datetime (const char *input, const char *fmt,
 		  }
 	      }
 	      break;
-		      
+
+	    case 'Z':
+	      /* Time-zone in abbreviated form */
+	      {
+		char tzs[6];
+		p = mu_str_skip_class_comp (input, MU_CTYPE_SPACE);
+		n = p - input;
+		if (n > sizeof (tzs) - 1)
+		  {
+		    rc = MU_ERR_PARSE;
+		    break;
+		  }
+		memcpy (tzs, input, n);
+		tzs[n] = 0;
+		if (mu_timezone_offset (tzs, &n))
+		  {
+		    rc = MU_ERR_PARSE;
+		    break;
+		  }
+		if (tz)
+		  tz->utc_offset = n;
+		input = p;
+	      }
+	      break;
+	      
 	    case '%':
 	      if (*input == '%')
 		input++;