From b2076c0500b4a987770e8f439d02ca3b98719669 Mon Sep 17 00:00:00 2001
From: daniel <daniel.kinzler@wikimedia.de>
Date: Wed, 5 Sep 2012 20:09:19 +0200
Subject: [PATCH] [Bug 24782]: fix API paging for recentchanges

Combine timestampt and rcid to form a uniformely increasing unique ID for paging.

The patch was originally submitted by Sam Reed, I fixed it up a bit.

Change-Id: Icc43b62ffa7f70f2eba36e9a07141b0ef2e02aa8
---
 includes/api/ApiQueryRecentChanges.php | 29 +++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/includes/api/ApiQueryRecentChanges.php b/includes/api/ApiQueryRecentChanges.php
index 6acca673fe..24849bd899 100644
--- a/includes/api/ApiQueryRecentChanges.php
+++ b/includes/api/ApiQueryRecentChanges.php
@@ -149,6 +149,26 @@ class ApiQueryRecentChanges extends ApiQueryGeneratorBase {
 		$this->addTables( 'recentchanges' );
 		$index = array( 'recentchanges' => 'rc_timestamp' ); // May change
 		$this->addTimestampWhereRange( 'rc_timestamp', $params['dir'], $params['start'], $params['end'] );
+
+		if ( !is_null( $params['continue'] ) ) {
+			$cont = explode( '|', $params['continue'] );
+			if ( count( $cont ) != 2 ) {
+				$this->dieUsage( 'Invalid continue param. You should pass the ' .
+								'original value returned by the previous query', '_badcontinue' );
+			}
+
+			$timestamp = $this->getDB()->addQuotes( wfTimestamp( TS_MW, $cont[0] ) );
+			$id = intval( $cont[1] );
+			$op = $params['dir'] == 'descending' ? '<' : '>';
+
+			$this->addWhere(
+				"rc_timestamp $op $timestamp OR " .
+				"(rc_timestamp = $timestamp AND " .
+				"rc_id <= $id)"
+			);
+		}
+
+
 		$this->addWhereFld( 'rc_namespace', $params['namespace'] );
 		$this->addWhereFld( 'rc_deleted', 0 );
 
@@ -229,8 +249,9 @@ class ApiQueryRecentChanges extends ApiQueryGeneratorBase {
 				$this->dieUsage( 'You need the patrol right to request the patrolled flag', 'permissiondenied' );
 			}
 
+			$this->addFields( 'rc_id' );
 			/* Add fields to our query if they are specified as a needed parameter. */
-			$this->addFieldsIf( array( 'rc_id', 'rc_this_oldid', 'rc_last_oldid' ), $this->fld_ids );
+			$this->addFieldsIf( array( 'rc_this_oldid', 'rc_last_oldid' ), $this->fld_ids );
 			$this->addFieldsIf( 'rc_comment', $this->fld_comment || $this->fld_parsedcomment );
 			$this->addFieldsIf( 'rc_user', $this->fld_user );
 			$this->addFieldsIf( 'rc_user_text', $this->fld_user || $this->fld_userid );
@@ -281,7 +302,7 @@ class ApiQueryRecentChanges extends ApiQueryGeneratorBase {
 		foreach ( $res as $row ) {
 			if ( ++ $count > $params['limit'] ) {
 				// We've reached the one extra which shows that there are additional pages to be had. Stop here...
-				$this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->rc_timestamp ) );
+				$this->setContinueEnumParameter( 'continue', wfTimestamp( TS_ISO_8601, $row->rc_timestamp ) . '|' . $row->rc_id );
 				break;
 			}
 
@@ -295,7 +316,7 @@ class ApiQueryRecentChanges extends ApiQueryGeneratorBase {
 				}
 				$fit = $result->addValue( array( 'query', $this->getModuleName() ), null, $vals );
 				if ( !$fit ) {
-					$this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->rc_timestamp ) );
+					$this->setContinueEnumParameter( 'continue', wfTimestamp( TS_ISO_8601, $row->rc_timestamp ) . '|' . $row->rc_id );
 					break;
 				}
 			} else {
@@ -584,6 +605,7 @@ class ApiQueryRecentChanges extends ApiQueryGeneratorBase {
 				)
 			),
 			'toponly' => false,
+			'continue' => null,
 		);
 	}
 
@@ -621,6 +643,7 @@ class ApiQueryRecentChanges extends ApiQueryGeneratorBase {
 			'limit' => 'How many total changes to return',
 			'tag' => 'Only list changes tagged with this tag',
 			'toponly' => 'Only list changes which are the latest revision',
+			'continue' => 'When more results are available, use this to continue',
 		);
 	}
 
-- 
2.20.1