From ebc746dcc29d2e1d9dfdd79f4161975243b1d0a8 Mon Sep 17 00:00:00 2001
From: Andrew Nicols <andrew@nicols.co.uk>
Date: Wed, 26 Oct 2016 15:43:54 +0800
Subject: [PATCH] MDL-56090 message: Make key in union unique

This also fixes the unit test to use the correct indices.
---
 message/classes/helper.php    |  7 +++++--
 message/tests/events_test.php | 24 ++++++++++++------------
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/message/classes/helper.php b/message/classes/helper.php
index 4a54d81026c..4fe71226aa9 100644
--- a/message/classes/helper.php
+++ b/message/classes/helper.php
@@ -49,14 +49,17 @@ class helper {
                                         $sort = 'timecreated ASC') {
         global $DB;
 
-        $sql = "SELECT id, useridfrom, useridto, subject, fullmessage, fullmessagehtml, fullmessageformat,
+        $messageid = $DB->sql_concat("'message_'", 'id');
+        $messagereadid = $DB->sql_concat("'messageread_'", 'id');
+
+        $sql = "SELECT {$messageid} AS fakeid, id, useridfrom, useridto, subject, fullmessage, fullmessagehtml, fullmessageformat,
                        smallmessage, notification, timecreated, 0 as timeread
                   FROM {message} m
                  WHERE ((useridto = ? AND useridfrom = ? AND timeusertodeleted = ?)
                     OR (useridto = ? AND useridfrom = ? AND timeuserfromdeleted = ?))
                    AND notification = 0
              UNION ALL
-                SELECT id, useridfrom, useridto, subject, fullmessage, fullmessagehtml, fullmessageformat,
+                SELECT {$messagereadid} AS fakeid, id, useridfrom, useridto, subject, fullmessage, fullmessagehtml, fullmessageformat,
                        smallmessage, notification, timecreated, timeread
                   FROM {message_read} mr
                  WHERE ((useridto = ? AND useridfrom = ? AND timeusertodeleted = ?)
diff --git a/message/tests/events_test.php b/message/tests/events_test.php
index b9309f580ad..1e3bc9e78c1 100644
--- a/message/tests/events_test.php
+++ b/message/tests/events_test.php
@@ -321,33 +321,34 @@ class core_message_events_testcase extends advanced_testcase {
         $message->timeusertodeleted = 0;
         $message->timecreated = 1;
 
+        $messages = [];
         // Send this a few times.
-        $messageid1 = $DB->insert_record('message', $message);
+        $messages[] = $DB->insert_record('message', $message);
 
         $message->timecreated++;
-        $messageid2 = $DB->insert_record('message', $message);
+        $messages[] = $DB->insert_record('message', $message);
 
         $message->timecreated++;
-        $messageid3 = $DB->insert_record('message', $message);
+        $messages[] = $DB->insert_record('message', $message);
 
         $message->timecreated++;
-        $messageid4 = $DB->insert_record('message', $message);
+        $messages[] = $DB->insert_record('message', $message);
 
         // Create a read message.
         $message->timeread = time();
 
         // Send this a few times.
         $message->timecreated++;
-        $messageid5 = $DB->insert_record('message_read', $message);
+        $messages[] = $DB->insert_record('message_read', $message);
 
         $message->timecreated++;
-        $messageid6 = $DB->insert_record('message_read', $message);
+        $messages[] = $DB->insert_record('message_read', $message);
 
         $message->timecreated++;
-        $messageid7 = $DB->insert_record('message_read', $message);
+        $messages[] = $DB->insert_record('message_read', $message);
 
         $message->timecreated++;
-        $messageid8 = $DB->insert_record('message_read', $message);
+        $messages[] = $DB->insert_record('message_read', $message);
 
         // Trigger and capture the event.
         $sink = $this->redirectEvents();
@@ -358,16 +359,15 @@ class core_message_events_testcase extends advanced_testcase {
         $this->assertEquals(8, count($events));
 
         // Check that the event data is valid.
-        $i = 1;
+        $i = 0;
         foreach ($events as $event) {
-            $table = ($i > 4) ? 'message_read' : 'message';
-            $messageid = 'messageid' . $i;
+            $table = ($i > 3) ? 'message_read' : 'message';
 
             $this->assertInstanceOf('\core\event\message_deleted', $event);
             $this->assertEquals($message->useridfrom, $event->userid);
             $this->assertEquals($message->useridto, $event->relateduserid);
             $this->assertEquals($table, $event->other['messagetable']);
-            $this->assertEquals($$messageid, $event->other['messageid']);
+            $this->assertEquals($messages[$i], $event->other['messageid']);
             $this->assertEquals($message->useridfrom, $event->other['useridfrom']);
             $this->assertEquals($message->useridto, $event->other['useridto']);