From 16509b590987a0b966a326b6d39d8a2d553582be Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian@liberator.(none)>
Date: Sun, 17 May 2009 02:47:22 +0100
Subject: [PATCH] Treat backwards-going timestamp as a day change.  Not perfect
 if the clocks change but what can you do.

---
 TODO             |  3 ---
 yoweb-scrape     | 18 ++++++++++++++----
 yoweb-scrape.txt |  8 ++++++++
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/TODO b/TODO
index 17e32cb..ecd5199 100644
--- a/TODO
+++ b/TODO
@@ -1,7 +1,4 @@
 yoweb-scrape
-	do right thing when chat log timestamp goes backwards:
-		assume it's the next day (will go wrong when
-		clocks go wrong - oh well)
 	parse officer chat for
 		/off /a [<ship>:] <pirate>...
 		/off /d [<ship>:] <pirate>...
diff --git a/yoweb-scrape b/yoweb-scrape
index c99b2b0..cc98ea3 100755
--- a/yoweb-scrape
+++ b/yoweb-scrape
@@ -482,7 +482,8 @@ class ChatLogTracker:
 
 		m = rm('=+ (\\d+)/(\\d+)/(\\d+) =+$')
 		if m:
-			self._date = m.groups()
+			self._date = [int(x) for x in m.groups()]
+			self._previous_timestamp = None
 			return d('date '+`self._date`)
 
 		if self._date is None:
@@ -492,9 +493,18 @@ class ChatLogTracker:
 		if not m:
 			return d('no timestamp')
 
-		time_tuple = [int(x) for x in self._date + m.groups()]
-		time_tuple += (-1,-1,-1)
-		timestamp = time.mktime(time_tuple)
+		while True:
+			time_tuple = (self._date +
+				      [int(x) for x in m.groups()] +
+				      [-1,-1,-1])
+			timestamp = time.mktime(time_tuple)
+			if timestamp >= self._previous_timestamp: break
+			self._date[2] += 1
+			self._debug_line_disposition(timestamp,'',
+				'new date '+`self._date`)
+
+		self._previous_timestamp = timestamp
+
 		l = l[l.find(' ')+1:]
 
 		def ob_x(who,event):
diff --git a/yoweb-scrape.txt b/yoweb-scrape.txt
index 2878be4..84368c5 100644
--- a/yoweb-scrape.txt
+++ b/yoweb-scrape.txt
@@ -73,6 +73,14 @@ Other things to mention:
  * I haven't decided on a final copyright licence.  You may treat this
    version as GPLv3.
 
+ * The program will become confused when the clocks change,
+   particularly when they go backwards.  This is due to the chat log
+   containing timestamps in local time without a timezone.  If this
+   bothers you, make everything be in UTC.  If it does get confused,
+   you can fix it by logging off and logging on again (perhaps waiting
+   until after the duplicated hour has passed) as that writes a new
+   date record to the log and starts a new series of timestamps.
+
 Ian.
 
 
-- 
2.30.2