1 files changed, 104 insertions, 0 deletions
diff --git a/maintenance/fixTimestamps.php b/maintenance/fixTimestamps.php
new file mode 100644
index 00000000..784e35cd
--- /dev/null
+++ b/maintenance/fixTimestamps.php
@@ -0,0 +1,104 @@
+<?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 );
+
+if ( is_null( $row->minrev ) ) {
+	echo "No revisions in search period.\n";
+	exit(0);
+}
+
+$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 == 0 ? 0 : $delta / abs( $delta );
+	if ( $sign == 0 || $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( $res );
+
+$numBadRevs = count( $badRevs );
+if ( $numBadRevs > $numGoodRevs ) {
+	echo 
+"The majority of revisions in the search interval are marked as bad.
+
+Are you sure the offset ($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);
+} elseif ( $numBadRevs == 0 ) {
+	echo "No bad revisions found.\n";
+	exit(0);
+}
+
+printf( "Fixing %d revisions (%.2f%% of revisions in search interval)\n", 
+	$numBadRevs, $numBadRevs / ($numGoodRevs + $numBadRevs) * 100 );
+
+$fixup = -$offset;
+$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\n";
+$dbw->query( $sql, $fname );
+echo "Done\n";
+
+?>