From 5666353f5e256d69558b92aaace43e8894126ee1 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Mon, 10 Apr 2006 07:21:40 +0000
Subject: [PATCH] Untested fixup script, committing for test on wikimedia
 cluster.

---
 maintenance/fixTimestamps.php | 93 +++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 maintenance/fixTimestamps.php

diff --git a/maintenance/fixTimestamps.php b/maintenance/fixTimestamps.php
new file mode 100644
index 0000000000..ef1c018a9f
--- /dev/null
+++ b/maintenance/fixTimestamps.php
@@ -0,0 +1,93 @@
+<?php
+
+/**
+ * This script fixes timestamp corruption caused by one or more webservers 
+ * temporarily being set to the wrong time. The time offset must be known and
+ * consistent. Start and end times (in 14-character format) restrict the search, 
+ * and must bracket the damage. There must be a majority of good timestamps in the 
+ * search period.
+ */
+
+require_once( 'commandLine.inc' );
+
+if ( count( $args ) < 3 ) {
+	echo "Usage: php fixTimestamps.php <offset in hours> <start time> <end time>\n";
+	exit(1);
+}
+
+$offset = $args[0] * 3600;
+$start = $args[1];
+$end = $args[2];
+$fname = 'fixTimestamps.php';
+$grace = 60; // maximum normal clock offset
+
+# Find bounding revision IDs
+$dbw =& wfGetDB( DB_MASTER );
+$revisionTable = $dbw->tableName( 'revision' );
+$res = $dbw->query( "SELECT MIN(rev_id) as minrev, MAX(rev_id) as maxrev FROM $revisionTable " .
+	"WHERE rev_timestamp BETWEEN $start AND $end", $fname );
+$row = $dbw->fetchObject( $res );
+$minRev = $row->minrev;
+$maxRev = $row->maxrev;
+
+# Select all timestamps and IDs
+$sql = "SELECT rev_id, rev_timestamp FROM $revisionTable " .
+	"WHERE rev_id BETWEEN $minRev AND $maxRev";
+if ( $offset > 0 ) {
+	$sql .= " ORDER BY rev_id DESC";
+	$expectedSign = -1;
+} else {
+	$expectedSign = 1;
+}
+
+$res = $dbw->query( $sql, $fname );
+
+$lastNormal = 0;
+$badRevs = array();
+$numGoodRevs = 0;
+
+while ( $row = $dbw->fetchObject( $res ) ) {
+	$timestamp = wfTimestamp( TS_UNIX, $row->rev_timestamp );
+	$delta = $timestamp - $lastNormal;
+	$sign = $delta / abs( $delta );
+	if ( $sign == $expectedSign ) {
+		// Monotonic change
+		$lastNormal = $timestamp;
+		++ $numGoodRevs;
+		continue;
+	} elseif ( abs( $delta ) <= $grace ) {
+		// Non-monotonic change within grace interval
+		++ $numGoodRevs;
+		continue;
+	} else {
+		// Non-monotonic change larger than grace interval
+		$badRevs[] = $row->rev_id;
+	}
+}
+$dbw->freeResult( $res );
+
+if ( count( $badRevs ) > $numGoodRevs ) {
+	echo 
+"The majority of revisions in the search interval are marked as bad.
+
+Are you sure the offset ($offset) has the right sign? Positive means the clock 
+was incorrectly set forward, negative means the clock was incorrectly set back.
+
+If the offset is right, then increase the search interval until there are enough 
+good revisions to provide a majority reference.
+";
+
+	exit(1);
+}
+
+printf( "Fixing %d revisions (%.2f%% of revisions in search interval)\n", 
+	count( $badRevs ), count($badRevs) / $numGoodRevs * 100 );
+
+$sql = "UPDATE $revisionTable " .
+	"SET rev_timestamp=DATE_FORMAT(DATE_ADD(rev_timestamp, INTERVAL $fixup SECOND), '%Y%m%d%H%i%s') " .
+	"WHERE rev_id IN (" . $dbw->makeList( $badRevs ) . ')';
+echo $sql;
+//$dbw->query( $sql, $fname );
+//echo "Done\n";
+
+?>
-- 
2.20.1