From: Amir Sarabadani <ladsgroup@gmail.com>
Date: Mon, 24 Apr 2017 12:58:51 +0000 (+0430)
Subject: Do not add limit to ApiQueryPagePropNames when database type is mysql
X-Git-Tag: 1.31.0-rc.0~3415^2
X-Git-Url: https://git.cyclocoop.org/%7B%7B%20url_for%28%27static%27%2C%20filename=%27css/bootstrap.css%27%29%20%7D%7D?a=commitdiff_plain;h=e2ad38f8e94838a90ccc151d554969cf81558839;p=lhc%2Fweb%2Fwiklou.git

Do not add limit to ApiQueryPagePropNames when database type is mysql

It's a known bug in some versions of mysql (including WMF dbs) that it
won't do a loose index scan when a limit is applied. Given that number
of possible types is still very low, this shouldn't be a problem.
More info: https://bugs.mysql.com/bug.php?id=61517

Bug: T115825
Change-Id: I4c3b885ac05b793088a92e054a38a36b9d07c0d4
---

diff --git a/includes/api/ApiQueryPagePropNames.php b/includes/api/ApiQueryPagePropNames.php
index 4966bcde04..ff97668117 100644
--- a/includes/api/ApiQueryPagePropNames.php
+++ b/includes/api/ApiQueryPagePropNames.php
@@ -57,7 +57,11 @@ class ApiQueryPagePropNames extends ApiQueryBase {
 		}
 
 		$limit = $params['limit'];
-		$this->addOption( 'LIMIT', $limit + 1 );
+
+		// mysql has issues with limit in loose index T115825
+		if ( $this->getDB()->getType() !== 'mysql' ) {
+			$this->addOption( 'LIMIT', $limit + 1 );
+		}
 
 		$result = $this->getResult();
 		$count = 0;