From 3db43d5a39813f852bad8f4fe90e4c27400b7fae Mon Sep 17 00:00:00 2001
From: Friendika <info@friendika.com>
Date: Wed, 12 Oct 2011 02:21:18 -0700
Subject: [PATCH] storage race condition

---
 include/items.php | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/include/items.php b/include/items.php
index 4862ca578..2c23c6f1b 100644
--- a/include/items.php
+++ b/include/items.php
@@ -677,7 +677,7 @@ function item_store($arr,$force_parent = false) {
 
 	if($arr['gravity'])
 		$arr['gravity'] = intval($arr['gravity']);
-	elseif($arr['parent-uri'] == $arr['uri'])
+	elseif($arr['parent-uri'] === $arr['uri'])
 		$arr['gravity'] = 0;
 	elseif(activity_match($arr['verb'],ACTIVITY_POST))
 		$arr['gravity'] = 6;
@@ -744,7 +744,7 @@ function item_store($arr,$force_parent = false) {
 		// find the parent and snarf the item id and ACL's
 		// and anything else we need to inherit
 
-		$r = q("SELECT * FROM `item` WHERE `uri` = '%s' AND `uid` = %d LIMIT 1",
+		$r = q("SELECT * FROM `item` WHERE `uri` = '%s' AND `uid` = %d ORDER BY `id` ASC LIMIT 1",
 			dbesc($arr['parent-uri']),
 			intval($arr['uid'])
 		);
@@ -758,7 +758,8 @@ function item_store($arr,$force_parent = false) {
 			if($r[0]['uri'] != $r[0]['parent-uri']) {
 				$arr['thr-parent'] = $arr['parent-uri'];
 				$arr['parent-uri'] = $r[0]['parent-uri'];
-				$z = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `parent-uri` = '%s' AND `uid` = %d LIMIT 1",
+				$z = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `parent-uri` = '%s' AND `uid` = %d 
+					ORDER BY `id` ASC LIMIT 1",
 					dbesc($r[0]['parent-uri']),
 					dbesc($r[0]['parent-uri']),
 					intval($arr['uid'])
@@ -796,7 +797,7 @@ function item_store($arr,$force_parent = false) {
 
 	$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = %d LIMIT 1",
 		dbesc($arr['uri']),
-		dbesc($arr['uid'])
+		intval($arr['uid'])
 	);
 	if($r && count($r)) {
 		logger('item-store: duplicate item ignored. ' . print_r($arr,true));
@@ -817,14 +818,14 @@ function item_store($arr,$force_parent = false) {
 
 	// find the item we just created
 
-	$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = %d LIMIT 1",
+	$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = %d LIMIT 1 ORDER BY `id` ASC",
 		$arr['uri'],           // already dbesc'd
 		intval($arr['uid'])
 	);
 	if(! count($r)) {
 		// This is not good, but perhaps we encountered a rare race/cache condition, so back off and try again. 
 		sleep(3);
-		$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = %d LIMIT 1",
+		$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = %d LIMIT 1 ORDER BY `id` ASC",
 			$arr['uri'],           // already dbesc'd
 			intval($arr['uid'])
 		);
@@ -838,6 +839,14 @@ function item_store($arr,$force_parent = false) {
 		logger('item_store: could not locate created item');
 		return 0;
 	}
+	if(count($r) > 1) {
+		logger('item_store: duplicated post occurred. Removing duplicates.');
+		q("DELETE FROM `item` WHERE `uri` = '%s' AND `uid` = %d AND `id` != %d ",
+			$arr['uri'],
+			intval($arr['uid']),
+			intval($current_post)
+		);
+	}
 
 	if((! $parent_id) || ($arr['parent-uri'] === $arr['uri']))	
 		$parent_id = $current_post;
@@ -2398,8 +2407,8 @@ function atom_entry($item,$type,$author,$owner,$comment = false) {
 	if(strlen($item['owner-name']))
 		$o .= atom_author('dfrn:owner',$item['owner-name'],$item['owner-link'],80,80,$item['owner-avatar']);
 
-	if($item['parent'] != $item['id'])
-		$o .= '<thr:in-reply-to ref="' . xmlify($item['parent-uri']) . '" type="text/html" href="' .  xmlify($a->get_baseurl() . '/display/' . $owner['nickname'] . '/' . $item['id']) . '" />' . "\r\n";
+	if(($item['parent'] != $item['id']) || ($item['parent-uri'] !== $item['uri']))
+		$o .= '<thr:in-reply-to ref="' . xmlify($item['parent-uri']) . '" type="text/html" href="' .  xmlify($a->get_baseurl() . '/display/' . $owner['nickname'] . '/' . $item['parent']) . '" />' . "\r\n";
 
 	$o .= '<id>' . xmlify($item['uri']) . '</id>' . "\r\n";
 	$o .= '<title>' . xmlify($item['title']) . '</title>' . "\r\n";