From cac526294c2eebde8d29a4d83774fe450f0d17d8 Mon Sep 17 00:00:00 2001
From: mudrd8mz <mudrd8mz>
Date: Mon, 2 Mar 2009 21:36:50 +0000
Subject: [PATCH] MDL-17492 Reset flag did not work in PostgreSQL

Postgres does not seem to support table alias in UPDATE statement.
Therefore the SQL like
 UPDATE mdl_tag tg SET tg.flag = 0, tg.timemodified = 1236027984 WHERE tg.id IN (4)
ends with an ERROR: column "tg" of relation "mdl_tag" does not exist
The fix is quite easy - just do not use table alias as it makes no sense
here anyway.
Besides this, the commit also fixes:
* do not try to access the array key [0] in case of empty array (no tags
  exist yet)
* do not require_capability() at the function level - it is already
  checked at the caller script level
---
 tag/lib.php      | 4 +---
 tag/locallib.php | 6 ++++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tag/lib.php b/tag/lib.php
index bc14eeba4bc..9f723408ea8 100644
--- a/tag/lib.php
+++ b/tag/lib.php
@@ -992,13 +992,11 @@ function tag_set_flag($tagids) {
 function tag_unset_flag($tagids) {
     global $CFG;
 
-    require_capability('moodle/tag:manage', get_context_instance(CONTEXT_SYSTEM));
-
     if ( is_array($tagids) ) {
         $tagids = implode(',', $tagids);
     }
     $timemodified = time();
-    return execute_sql("UPDATE {$CFG->prefix}tag tg SET tg.flag = 0, tg.timemodified = $timemodified WHERE tg.id IN ($tagids)", false);
+    return execute_sql("UPDATE {$CFG->prefix}tag SET flag = 0, timemodified = $timemodified WHERE id IN ($tagids)", false);
 }
 
 ?>
diff --git a/tag/locallib.php b/tag/locallib.php
index bef8a7e2fd0..615d189af1f 100644
--- a/tag/locallib.php
+++ b/tag/locallib.php
@@ -30,8 +30,10 @@ function tag_print_cloud($nr_of_tags=150, $return=false) {
     }
 
     $tagkeys = array_keys($tagsincloud);
-    $firsttagkey = $tagkeys[0];
-    $maxcount = $tagsincloud[$firsttagkey]->count;
+    if (!empty($tagkeys)) {
+        $firsttagkey = $tagkeys[0];
+        $maxcount = $tagsincloud[$firsttagkey]->count;
+    }
 
     $etags = array();