1 files changed, 83 insertions, 0 deletions
diff --git a/maintenance/populateParentId.inc b/maintenance/populateParentId.inc
new file mode 100644
index 00000000..3fecc63b
--- /dev/null
+++ b/maintenance/populateParentId.inc
@@ -0,0 +1,83 @@
+<?php
+
+define( 'BATCH_SIZE', 200 );
+
+function populate_rev_parent_id( $db ) {
+	echo "Populating rev_parent_id column\n";
+	$start = $db->selectField( 'revision', 'MIN(rev_id)', false, __FUNCTION__ );
+	$end = $db->selectField( 'revision', 'MAX(rev_id)', false, __FUNCTION__ );
+	if( is_null( $start ) || is_null( $end ) ){
+		echo "...revision table seems to be empty.\n";
+		$db->insert( 'updatelog',
+			array( 'ul_key' => 'populate rev_parent_id' ),
+			__FUNCTION__,
+			'IGNORE' );
+		return;
+	}
+	# Do remaining chunk
+	$end += BATCH_SIZE - 1;
+	$blockStart = $start;
+	$blockEnd = $start + BATCH_SIZE - 1;
+	$count = 0;
+	$changed = 0;
+	while( $blockEnd <= $end ) {
+		echo "...doing rev_id from $blockStart to $blockEnd\n";
+		$cond = "rev_id BETWEEN $blockStart AND $blockEnd";
+		$res = $db->select( 'revision', 
+			array('rev_id','rev_page','rev_timestamp','rev_parent_id'), 
+			$cond, __FUNCTION__ );
+		# Go through and update rev_parent_id from these rows.
+		# Assume that the previous revision of the title was
+		# the original previous revision of the title when the
+		# edit was made...
+		foreach( $res as $row ) {
+			# First, check rows with the same timestamp other than this one
+			# with a smaller rev ID. The highest ID "wins". This avoids loops
+			# as timestamp can only decrease and never loops with IDs (from parent to parent)
+			$previousID = $db->selectField( 'revision', 'rev_id', 
+				array( 'rev_page' => $row->rev_page, 'rev_timestamp' => $row->rev_timestamp,
+					"rev_id < {$row->rev_id}" ), 
+				__FUNCTION__,
+				array( 'ORDER BY' => 'rev_id DESC' ) );
+			# If there are none, check the the highest ID with a lower timestamp
+			if( !$previousID ) {
+				# Get the highest older timestamp
+				$lastTimestamp = $db->selectField( 'revision', 'rev_timestamp', 
+					array( 'rev_page' => $row->rev_page, "rev_timestamp < '{$row->rev_timestamp}'" ), 
+					__FUNCTION__,
+					array( 'ORDER BY' => 'rev_timestamp DESC' ) );
+				# If there is one, let the highest rev ID win
+				if( $lastTimestamp ) {
+					$previousID = $db->selectField( 'revision', 'rev_id', 
+						array( 'rev_page' => $row->rev_page, 'rev_timestamp' => $lastTimestamp ), 
+						__FUNCTION__,
+						array( 'ORDER BY' => 'rev_id DESC' ) );
+				}
+			}
+			$previousID = intval($previousID);
+			if( $previousID != $row->rev_parent_id )
+				$changed++;
+			# Update the row...
+			$db->update( 'revision',
+				array( 'rev_parent_id' => $previousID ),
+				array( 'rev_id' => $row->rev_id ),
+				__FUNCTION__ );
+			$count++;
+		}
+		$blockStart += BATCH_SIZE - 1;
+		$blockEnd += BATCH_SIZE - 1;
+		wfWaitForSlaves( 5 );
+	}
+	$logged = $db->insert( 'updatelog',
+		array( 'ul_key' => 'populate rev_parent_id' ),
+		__FUNCTION__,
+		'IGNORE' );
+	if( $logged ) {
+		echo "rev_parent_id population complete ... {$count} rows [{$changed} changed]\n";
+		return true;
+	} else {
+		echo "Could not insert rev_parent_id population row.\n";
+		return false;
+	}
+}
+