10 files changed, 251 insertions, 142 deletions
diff --git a/phpBB/phpbb/db/driver/driver.php b/phpBB/phpbb/db/driver/driver.php
index 9fc04d47a1..8d360fc3e2 100644
--- a/phpBB/phpbb/db/driver/driver.php
+++ b/phpBB/phpbb/db/driver/driver.php
@@ -271,7 +271,7 @@ abstract class driver implements driver_interface
 			$query_id = $this->query_result;
 		}
 
-		if ($query_id !== false)
+		if ($query_id)
 		{
 			$result = array();
 			while ($row = $this->sql_fetchrow($query_id))
@@ -302,7 +302,7 @@ abstract class driver implements driver_interface
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
 
-		if ($query_id === false)
+		if (!$query_id)
 		{
 			return false;
 		}
@@ -310,7 +310,7 @@ abstract class driver implements driver_interface
 		$this->sql_freeresult($query_id);
 		$query_id = $this->sql_query($this->last_query_text);
 
-		if ($query_id === false)
+		if (!$query_id)
 		{
 			return false;
 		}
@@ -339,7 +339,7 @@ abstract class driver implements driver_interface
 			$query_id = $this->query_result;
 		}
 
-		if ($query_id !== false)
+		if ($query_id)
 		{
 			if ($rownum !== false)
 			{
@@ -363,8 +363,8 @@ abstract class driver implements driver_interface
 	*/
 	function sql_like_expression($expression)
 	{
-		$expression = utf8_str_replace(array('_', '%'), array("\_", "\%"), $expression);
-		$expression = utf8_str_replace(array(chr(0) . "\_", chr(0) . "\%"), array('_', '%'), $expression);
+		$expression = str_replace(array('_', '%'), array("\_", "\%"), $expression);
+		$expression = str_replace(array(chr(0) . "\_", chr(0) . "\%"), array('_', '%'), $expression);
 
 		return $this->_sql_like_expression('LIKE \'' . $this->sql_escape($expression) . '\'');
 	}
@@ -374,8 +374,8 @@ abstract class driver implements driver_interface
 	*/
 	function sql_not_like_expression($expression)
 	{
-		$expression = utf8_str_replace(array('_', '%'), array("\_", "\%"), $expression);
-		$expression = utf8_str_replace(array(chr(0) . "\_", chr(0) . "\%"), array('_', '%'), $expression);
+		$expression = str_replace(array('_', '%'), array("\_", "\%"), $expression);
+		$expression = str_replace(array(chr(0) . "\_", chr(0) . "\%"), array('_', '%'), $expression);
 
 		return $this->_sql_not_like_expression('NOT LIKE \'' . $this->sql_escape($expression) . '\'');
 	}
diff --git a/phpBB/phpbb/db/driver/mssql.php b/phpBB/phpbb/db/driver/mssql.php
index f9ea884ce2..dfdbfe15e6 100644
--- a/phpBB/phpbb/db/driver/mssql.php
+++ b/phpBB/phpbb/db/driver/mssql.php
@@ -71,8 +71,8 @@ class mssql extends \phpbb\db\driver\driver
 			$row = false;
 			if ($result_id)
 			{
-				$row = @mssql_fetch_assoc($result_id);
-				@mssql_free_result($result_id);
+				$row = mssql_fetch_assoc($result_id);
+				mssql_free_result($result_id);
 			}
 
 			$this->sql_server_version = ($row) ? trim(implode(' ', $row)) : 0;
@@ -161,12 +161,17 @@ class mssql extends \phpbb\db\driver\driver
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+				else if (strpos($query, 'SELECT') === 0 && $this->query_result !== true)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
@@ -241,12 +246,12 @@ class mssql extends \phpbb\db\driver\driver
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		if ($query_id === false)
+		if (!$query_id || $query_id === true)
 		{
 			return false;
 		}
 
-		$row = @mssql_fetch_assoc($query_id);
+		$row = mssql_fetch_assoc($query_id);
 
 		// I hope i am able to remove this later... hopefully only a PHP or MSSQL bug
 		if ($row)
@@ -272,12 +277,17 @@ class mssql extends \phpbb\db\driver\driver
 			$query_id = $this->query_result;
 		}
 
+		if ($query_id === true)
+		{
+			return false;
+		}
+
 		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
 
-		return ($query_id !== false) ? @mssql_data_seek($query_id, $rownum) : false;
+		return ($query_id) ? @mssql_data_seek($query_id, $rownum) : false;
 	}
 
 	/**
@@ -288,12 +298,12 @@ class mssql extends \phpbb\db\driver\driver
 		$result_id = @mssql_query('SELECT SCOPE_IDENTITY()', $this->db_connect_id);
 		if ($result_id)
 		{
-			if ($row = @mssql_fetch_assoc($result_id))
+			if ($row = mssql_fetch_assoc($result_id))
 			{
-				@mssql_free_result($result_id);
+				mssql_free_result($result_id);
 				return $row['computed'];
 			}
-			@mssql_free_result($result_id);
+			mssql_free_result($result_id);
 		}
 
 		return false;
@@ -311,6 +321,11 @@ class mssql extends \phpbb\db\driver\driver
 			$query_id = $this->query_result;
 		}
 
+		if ($query_id === true)
+		{
+			return false;
+		}
+
 		if ($cache && !is_object($query_id) && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
@@ -319,7 +334,7 @@ class mssql extends \phpbb\db\driver\driver
 		if (isset($this->open_queries[(int) $query_id]))
 		{
 			unset($this->open_queries[(int) $query_id]);
-			return @mssql_free_result($query_id);
+			return mssql_free_result($query_id);
 		}
 
 		return false;
@@ -376,9 +391,9 @@ class mssql extends \phpbb\db\driver\driver
 			$result_id = @mssql_query('SELECT @@ERROR as code', $this->db_connect_id);
 			if ($result_id)
 			{
-				$row = @mssql_fetch_assoc($result_id);
+				$row = mssql_fetch_assoc($result_id);
 				$error['code'] = $row['code'];
-				@mssql_free_result($result_id);
+				mssql_free_result($result_id);
 			}
 
 			// Get full error message if possible
@@ -389,12 +404,12 @@ class mssql extends \phpbb\db\driver\driver
 
 			if ($result_id)
 			{
-				$row = @mssql_fetch_assoc($result_id);
+				$row = mssql_fetch_assoc($result_id);
 				if (!empty($row['message']))
 				{
 					$error['message'] .= '<br />' . $row['message'];
 				}
-				@mssql_free_result($result_id);
+				mssql_free_result($result_id);
 			}
 		}
 		else
@@ -440,13 +455,13 @@ class mssql extends \phpbb\db\driver\driver
 				if ($result = @mssql_query($query, $this->db_connect_id))
 				{
 					@mssql_next_result($result);
-					while ($row = @mssql_fetch_row($result))
+					while ($row = mssql_fetch_row($result))
 					{
 						$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 					}
 				}
 				@mssql_query('SET SHOWPLAN_TEXT OFF;', $this->db_connect_id);
-				@mssql_free_result($result);
+				mssql_free_result($result);
 
 				if ($html_table)
 				{
@@ -459,11 +474,14 @@ class mssql extends \phpbb\db\driver\driver
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @mssql_query($query, $this->db_connect_id);
-				while ($void = @mssql_fetch_assoc($result))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					while ($void = mssql_fetch_assoc($result))
+					{
+						// Take the time spent on parsing rows into account
+					}
+					mssql_free_result($result);
 				}
-				@mssql_free_result($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/mssql_odbc.php b/phpBB/phpbb/db/driver/mssql_odbc.php
index 8e5d4c7a4c..9d9ad603e0 100644
--- a/phpBB/phpbb/db/driver/mssql_odbc.php
+++ b/phpBB/phpbb/db/driver/mssql_odbc.php
@@ -98,8 +98,8 @@ class mssql_odbc extends \phpbb\db\driver\mssql_base
 			$row = false;
 			if ($result_id)
 			{
-				$row = @odbc_fetch_array($result_id);
-				@odbc_free_result($result_id);
+				$row = odbc_fetch_array($result_id);
+				odbc_free_result($result_id);
 			}
 
 			$this->sql_server_version = ($row) ? trim(implode(' ', $row)) : 0;
@@ -181,12 +181,17 @@ class mssql_odbc extends \phpbb\db\driver\mssql_base
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+				else if (strpos($query, 'SELECT') === 0)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
@@ -261,7 +266,7 @@ class mssql_odbc extends \phpbb\db\driver\mssql_base
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		return ($query_id !== false) ? @odbc_fetch_array($query_id) : false;
+		return ($query_id) ? odbc_fetch_array($query_id) : false;
 	}
 
 	/**
@@ -273,13 +278,13 @@ class mssql_odbc extends \phpbb\db\driver\mssql_base
 
 		if ($result_id)
 		{
-			if (@odbc_fetch_array($result_id))
+			if (odbc_fetch_array($result_id))
 			{
-				$id = @odbc_result($result_id, 1);
-				@odbc_free_result($result_id);
+				$id = odbc_result($result_id, 1);
+				odbc_free_result($result_id);
 				return $id;
 			}
-			@odbc_free_result($result_id);
+			odbc_free_result($result_id);
 		}
 
 		return false;
@@ -305,7 +310,7 @@ class mssql_odbc extends \phpbb\db\driver\mssql_base
 		if (isset($this->open_queries[(int) $query_id]))
 		{
 			unset($this->open_queries[(int) $query_id]);
-			return @odbc_free_result($query_id);
+			return odbc_free_result($query_id);
 		}
 
 		return false;
@@ -360,11 +365,14 @@ class mssql_odbc extends \phpbb\db\driver\mssql_base
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @odbc_exec($this->db_connect_id, $query);
-				while ($void = @odbc_fetch_array($result))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					while ($void = odbc_fetch_array($result))
+					{
+						// Take the time spent on parsing rows into account
+					}
+					odbc_free_result($result);
 				}
-				@odbc_free_result($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/mssqlnative.php b/phpBB/phpbb/db/driver/mssqlnative.php
index 46a9b3a477..50dce35baa 100644
--- a/phpBB/phpbb/db/driver/mssqlnative.php
+++ b/phpBB/phpbb/db/driver/mssqlnative.php
@@ -154,12 +154,17 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+				else if (strpos($query, 'SELECT') === 0)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
@@ -242,12 +247,12 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		if ($query_id === false)
+		if (!$query_id)
 		{
 			return false;
 		}
 
-		$row = @sqlsrv_fetch_array($query_id, SQLSRV_FETCH_ASSOC);
+		$row = sqlsrv_fetch_array($query_id, SQLSRV_FETCH_ASSOC);
 
 		if ($row)
 		{
@@ -272,11 +277,11 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 	{
 		$result_id = @sqlsrv_query($this->db_connect_id, 'SELECT @@IDENTITY');
 
-		if ($result_id !== false)
+		if ($result_id)
 		{
-			$row = @sqlsrv_fetch_array($result_id);
+			$row = sqlsrv_fetch_array($result_id);
 			$id = $row[0];
-			@sqlsrv_free_stmt($result_id);
+			sqlsrv_free_stmt($result_id);
 			return $id;
 		}
 		else
@@ -305,7 +310,7 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 		if (isset($this->open_queries[(int) $query_id]))
 		{
 			unset($this->open_queries[(int) $query_id]);
-			return @sqlsrv_free_stmt($query_id);
+			return sqlsrv_free_stmt($query_id);
 		}
 
 		return false;
@@ -378,14 +383,14 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 				@sqlsrv_query($this->db_connect_id, 'SET SHOWPLAN_TEXT ON;');
 				if ($result = @sqlsrv_query($this->db_connect_id, $query))
 				{
-					@sqlsrv_next_result($result);
-					while ($row = @sqlsrv_fetch_array($result))
+					sqlsrv_next_result($result);
+					while ($row = sqlsrv_fetch_array($result))
 					{
 						$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 					}
+					sqlsrv_free_stmt($result);
 				}
 				@sqlsrv_query($this->db_connect_id, 'SET SHOWPLAN_TEXT OFF;');
-				@sqlsrv_free_stmt($result);
 
 				if ($html_table)
 				{
@@ -398,11 +403,14 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @sqlsrv_query($this->db_connect_id, $query);
-				while ($void = @sqlsrv_fetch_array($result))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					while ($void = sqlsrv_fetch_array($result))
+					{
+						// Take the time spent on parsing rows into account
+					}
+					sqlsrv_free_stmt($result);
 				}
-				@sqlsrv_free_stmt($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/mysql.php b/phpBB/phpbb/db/driver/mysql.php
index e93c7239e8..a94e88b331 100644
--- a/phpBB/phpbb/db/driver/mysql.php
+++ b/phpBB/phpbb/db/driver/mysql.php
@@ -70,9 +70,16 @@ class mysql extends \phpbb\db\driver\mysql_base
 					if (version_compare($this->sql_server_info(true), '5.0.2', '>='))
 					{
 						$result = @mysql_query('SELECT @@session.sql_mode AS sql_mode', $this->db_connect_id);
-						$row = @mysql_fetch_assoc($result);
-						@mysql_free_result($result);
-						$modes = array_map('trim', explode(',', $row['sql_mode']));
+						if ($result)
+						{
+							$row = mysql_fetch_assoc($result);
+							mysql_free_result($result);
+							$modes = array_map('trim', explode(',', $row['sql_mode']));
+						}
+						else
+						{
+							$modes = array();
+						}
 
 						// TRADITIONAL includes STRICT_ALL_TABLES and STRICT_TRANS_TABLES
 						if (!in_array('TRADITIONAL', $modes))
@@ -114,14 +121,17 @@ class mysql extends \phpbb\db\driver\mysql_base
 		if (!$use_cache || empty($cache) || ($this->sql_server_version = $cache->get('mysql_version')) === false)
 		{
 			$result = @mysql_query('SELECT VERSION() AS version', $this->db_connect_id);
-			$row = @mysql_fetch_assoc($result);
-			@mysql_free_result($result);
+			if ($result)
+			{
+				$row = mysql_fetch_assoc($result);
+				mysql_free_result($result);
 
-			$this->sql_server_version = $row['version'];
+				$this->sql_server_version = $row['version'];
 
-			if (!empty($cache) && $use_cache)
-			{
-				$cache->put('mysql_version', $this->sql_server_version);
+				if (!empty($cache) && $use_cache)
+				{
+					$cache->put('mysql_version', $this->sql_server_version);
+				}
 			}
 		}
 
@@ -190,12 +200,17 @@ class mysql extends \phpbb\db\driver\mysql_base
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+				else if (strpos($query, 'SELECT') === 0)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
@@ -257,7 +272,7 @@ class mysql extends \phpbb\db\driver\mysql_base
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		return ($query_id !== false) ? @mysql_fetch_assoc($query_id) : false;
+		return ($query_id) ? mysql_fetch_assoc($query_id) : false;
 	}
 
 	/**
@@ -308,7 +323,7 @@ class mysql extends \phpbb\db\driver\mysql_base
 		if (isset($this->open_queries[(int) $query_id]))
 		{
 			unset($this->open_queries[(int) $query_id]);
-			return @mysql_free_result($query_id);
+			return mysql_free_result($query_id);
 		}
 
 		return false;
@@ -411,12 +426,12 @@ class mysql extends \phpbb\db\driver\mysql_base
 
 					if ($result = @mysql_query("EXPLAIN $explain_query", $this->db_connect_id))
 					{
-						while ($row = @mysql_fetch_assoc($result))
+						while ($row = mysql_fetch_assoc($result))
 						{
 							$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 						}
+						mysql_free_result($result);
 					}
-					@mysql_free_result($result);
 
 					if ($html_table)
 					{
@@ -431,7 +446,7 @@ class mysql extends \phpbb\db\driver\mysql_base
 						if ($result = @mysql_query('SHOW PROFILE ALL;', $this->db_connect_id))
 						{
 							$this->html_hold .= '<br />';
-							while ($row = @mysql_fetch_assoc($result))
+							while ($row = mysql_fetch_assoc($result))
 							{
 								// make <unknown> HTML safe
 								if (!empty($row['Source_function']))
@@ -449,8 +464,8 @@ class mysql extends \phpbb\db\driver\mysql_base
 								}
 								$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 							}
+							mysql_free_result($result);
 						}
-						@mysql_free_result($result);
 
 						if ($html_table)
 						{
@@ -468,11 +483,14 @@ class mysql extends \phpbb\db\driver\mysql_base
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @mysql_query($query, $this->db_connect_id);
-				while ($void = @mysql_fetch_assoc($result))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					while ($void = mysql_fetch_assoc($result))
+					{
+						// Take the time spent on parsing rows into account
+					}
+					mysql_free_result($result);
 				}
-				@mysql_free_result($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/mysqli.php b/phpBB/phpbb/db/driver/mysqli.php
index c0ddfbf76c..d43e201526 100644
--- a/phpBB/phpbb/db/driver/mysqli.php
+++ b/phpBB/phpbb/db/driver/mysqli.php
@@ -74,9 +74,10 @@ class mysqli extends \phpbb\db\driver\mysql_base
 			if (version_compare($this->sql_server_info(true), '5.0.2', '>='))
 			{
 				$result = @mysqli_query($this->db_connect_id, 'SELECT @@session.sql_mode AS sql_mode');
-				if ($result !== null)
+				if ($result)
 				{
-					$row = @mysqli_fetch_assoc($result);
+					$row = mysqli_fetch_assoc($result);
+					mysqli_free_result($result);
 
 					$modes = array_map('trim', explode(',', $row['sql_mode']));
 				}
@@ -84,7 +85,6 @@ class mysqli extends \phpbb\db\driver\mysql_base
 				{
 					$modes = array();
 				}
-				@mysqli_free_result($result);
 
 				// TRADITIONAL includes STRICT_ALL_TABLES and STRICT_TRANS_TABLES
 				if (!in_array('TRADITIONAL', $modes))
@@ -119,9 +119,10 @@ class mysqli extends \phpbb\db\driver\mysql_base
 		if (!$use_cache || empty($cache) || ($this->sql_server_version = $cache->get('mysqli_version')) === false)
 		{
 			$result = @mysqli_query($this->db_connect_id, 'SELECT VERSION() AS version');
-			if ($result !== null)
+			if ($result)
 			{
-				$row = @mysqli_fetch_assoc($result);
+				$row = mysqli_fetch_assoc($result);
+				mysqli_free_result($result);
 
 				$this->sql_server_version = $row['version'];
 
@@ -130,7 +131,6 @@ class mysqli extends \phpbb\db\driver\mysql_base
 					$cache->put('mysqli_version', $this->sql_server_version);
 				}
 			}
-			@mysqli_free_result($result);
 		}
 
 		return ($raw) ? $this->sql_server_version : 'MySQL(i) ' . $this->sql_server_version;
@@ -202,6 +202,11 @@ class mysqli extends \phpbb\db\driver\mysql_base
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
@@ -245,9 +250,9 @@ class mysqli extends \phpbb\db\driver\mysql_base
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		if ($query_id !== false && $query_id !== null)
+		if ($query_id)
 		{
-			$result = @mysqli_fetch_assoc($query_id);
+			$result = mysqli_fetch_assoc($query_id);
 			return $result !== null ? $result : false;
 		}
 
@@ -271,7 +276,7 @@ class mysqli extends \phpbb\db\driver\mysql_base
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
 
-		return ($query_id !== false) ? @mysqli_data_seek($query_id, $rownum) : false;
+		return ($query_id) ? @mysqli_data_seek($query_id, $rownum) : false;
 	}
 
 	/**
@@ -299,7 +304,17 @@ class mysqli extends \phpbb\db\driver\mysql_base
 			return $cache->sql_freeresult($query_id);
 		}
 
-		return @mysqli_free_result($query_id);
+		if (!$query_id)
+		{
+			return false;
+		}
+
+		if ($query_id === true)
+		{
+			return true;
+		}
+
+		return mysqli_free_result($query_id);
 	}
 
 	/**
@@ -398,12 +413,12 @@ class mysqli extends \phpbb\db\driver\mysql_base
 
 					if ($result = @mysqli_query($this->db_connect_id, "EXPLAIN $explain_query"))
 					{
-						while ($row = @mysqli_fetch_assoc($result))
+						while ($row = mysqli_fetch_assoc($result))
 						{
 							$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 						}
+						mysqli_free_result($result);
 					}
-					@mysqli_free_result($result);
 
 					if ($html_table)
 					{
@@ -418,7 +433,7 @@ class mysqli extends \phpbb\db\driver\mysql_base
 						if ($result = @mysqli_query($this->db_connect_id, 'SHOW PROFILE ALL;'))
 						{
 							$this->html_hold .= '<br />';
-							while ($row = @mysqli_fetch_assoc($result))
+							while ($row = mysqli_fetch_assoc($result))
 							{
 								// make <unknown> HTML safe
 								if (!empty($row['Source_function']))
@@ -436,8 +451,8 @@ class mysqli extends \phpbb\db\driver\mysql_base
 								}
 								$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 							}
+							mysqli_free_result($result);
 						}
-						@mysqli_free_result($result);
 
 						if ($html_table)
 						{
@@ -455,14 +470,14 @@ class mysqli extends \phpbb\db\driver\mysql_base
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @mysqli_query($this->db_connect_id, $query);
-				if ($result !== null)
+				if ($result)
 				{
-					while ($void = @mysqli_fetch_assoc($result))
+					while ($void = mysqli_fetch_assoc($result))
 					{
 						// Take the time spent on parsing rows into account
 					}
+					mysqli_free_result($result);
 				}
-				@mysqli_free_result($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/oracle.php b/phpBB/phpbb/db/driver/oracle.php
index 6dcab5dd7d..89e1b68aac 100644
--- a/phpBB/phpbb/db/driver/oracle.php
+++ b/phpBB/phpbb/db/driver/oracle.php
@@ -439,12 +439,17 @@ class oracle extends \phpbb\db\driver\driver
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+				else if (strpos($query, 'SELECT') === 0)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
@@ -499,10 +504,10 @@ class oracle extends \phpbb\db\driver\driver
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		if ($query_id !== false)
+		if ($query_id)
 		{
 			$row = array();
-			$result = @ocifetchinto($query_id, $row, OCI_ASSOC + OCI_RETURN_NULLS);
+			$result = ocifetchinto($query_id, $row, OCI_ASSOC + OCI_RETURN_NULLS);
 
 			if (!$result || !$row)
 			{
@@ -550,7 +555,7 @@ class oracle extends \phpbb\db\driver\driver
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
 
-		if ($query_id === false)
+		if (!$query_id)
 		{
 			return false;
 		}
@@ -583,18 +588,24 @@ class oracle extends \phpbb\db\driver\driver
 			{
 				$query = 'SELECT ' . $tablename[1] . '_seq.currval FROM DUAL';
 				$stmt = @ociparse($this->db_connect_id, $query);
-				@ociexecute($stmt, OCI_DEFAULT);
+				if ($stmt)
+				{
+					$success = @ociexecute($stmt, OCI_DEFAULT);
 
-				$temp_result = @ocifetchinto($stmt, $temp_array, OCI_ASSOC + OCI_RETURN_NULLS);
-				@ocifreestatement($stmt);
+					if ($success)
+					{
+						$temp_result = ocifetchinto($stmt, $temp_array, OCI_ASSOC + OCI_RETURN_NULLS);
+						ocifreestatement($stmt);
 
-				if ($temp_result)
-				{
-					return $temp_array['CURRVAL'];
-				}
-				else
-				{
-					return false;
+						if ($temp_result)
+						{
+							return $temp_array['CURRVAL'];
+						}
+						else
+						{
+							return false;
+						}
+					}
 				}
 			}
 		}
@@ -622,7 +633,7 @@ class oracle extends \phpbb\db\driver\driver
 		if (isset($this->open_queries[(int) $query_id]))
 		{
 			unset($this->open_queries[(int) $query_id]);
-			return @ocifreestatement($query_id);
+			return ocifreestatement($query_id);
 		}
 
 		return false;
@@ -787,14 +798,20 @@ class oracle extends \phpbb\db\driver\driver
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @ociparse($this->db_connect_id, $query);
-				$success = @ociexecute($result, OCI_DEFAULT);
-				$row = array();
-
-				while (@ocifetchinto($result, $row, OCI_ASSOC + OCI_RETURN_NULLS))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					$success = @ociexecute($result, OCI_DEFAULT);
+					if ($success)
+					{
+						$row = array();
+
+						while (ocifetchinto($result, $row, OCI_ASSOC + OCI_RETURN_NULLS))
+						{
+							// Take the time spent on parsing rows into account
+						}
+						@ocifreestatement($result);
+					}
 				}
-				@ocifreestatement($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/postgres.php b/phpBB/phpbb/db/driver/postgres.php
index a3b9aa4c6b..44476612c3 100644
--- a/phpBB/phpbb/db/driver/postgres.php
+++ b/phpBB/phpbb/db/driver/postgres.php
@@ -123,14 +123,17 @@ class postgres extends \phpbb\db\driver\driver
 		if (!$use_cache || empty($cache) || ($this->sql_server_version = $cache->get('pgsql_version')) === false)
 		{
 			$query_id = @pg_query($this->db_connect_id, 'SELECT VERSION() AS version');
-			$row = @pg_fetch_assoc($query_id, null);
-			@pg_free_result($query_id);
+			if ($query_id)
+			{
+				$row = pg_fetch_assoc($query_id, null);
+				pg_free_result($query_id);
 
-			$this->sql_server_version = (!empty($row['version'])) ? trim(substr($row['version'], 10)) : 0;
+				$this->sql_server_version = (!empty($row['version'])) ? trim(substr($row['version'], 10)) : 0;
 
-			if (!empty($cache) && $use_cache)
-			{
-				$cache->put('pgsql_version', $this->sql_server_version);
+				if (!empty($cache) && $use_cache)
+				{
+					$cache->put('pgsql_version', $this->sql_server_version);
+				}
 			}
 		}
 
@@ -200,12 +203,17 @@ class postgres extends \phpbb\db\driver\driver
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+				else if (strpos($query, 'SELECT') === 0)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
@@ -275,7 +283,7 @@ class postgres extends \phpbb\db\driver\driver
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		return ($query_id !== false) ? @pg_fetch_assoc($query_id, null) : false;
+		return ($query_id) ? pg_fetch_assoc($query_id, null) : false;
 	}
 
 	/**
@@ -295,7 +303,7 @@ class postgres extends \phpbb\db\driver\driver
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
 
-		return ($query_id !== false) ? @pg_result_seek($query_id, $rownum) : false;
+		return ($query_id) ? @pg_result_seek($query_id, $rownum) : false;
 	}
 
 	/**
@@ -317,8 +325,8 @@ class postgres extends \phpbb\db\driver\driver
 					return false;
 				}
 
-				$temp_result = @pg_fetch_assoc($temp_q_id, null);
-				@pg_free_result($query_id);
+				$temp_result = pg_fetch_assoc($temp_q_id, null);
+				pg_free_result($query_id);
 
 				return ($temp_result) ? $temp_result['last_value'] : false;
 			}
@@ -347,7 +355,7 @@ class postgres extends \phpbb\db\driver\driver
 		if (isset($this->open_queries[(int) $query_id]))
 		{
 			unset($this->open_queries[(int) $query_id]);
-			return @pg_free_result($query_id);
+			return pg_free_result($query_id);
 		}
 
 		return false;
@@ -453,12 +461,12 @@ class postgres extends \phpbb\db\driver\driver
 
 					if ($result = @pg_query($this->db_connect_id, "EXPLAIN $explain_query"))
 					{
-						while ($row = @pg_fetch_assoc($result, null))
+						while ($row = pg_fetch_assoc($result, null))
 						{
 							$html_table = $this->sql_report('add_select_row', $query, $html_table, $row);
 						}
+						pg_free_result($result);
 					}
-					@pg_free_result($result);
 
 					if ($html_table)
 					{
@@ -473,11 +481,14 @@ class postgres extends \phpbb\db\driver\driver
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @pg_query($this->db_connect_id, $query);
-				while ($void = @pg_fetch_assoc($result, null))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					while ($void = pg_fetch_assoc($result, null))
+					{
+						// Take the time spent on parsing rows into account
+					}
+					pg_free_result($result);
 				}
-				@pg_free_result($result);
 
 				$splittime = explode(' ', microtime());
 				$splittime = $splittime[0] + $splittime[1];
diff --git a/phpBB/phpbb/db/driver/sqlite.php b/phpBB/phpbb/db/driver/sqlite.php
index d5da0e2438..8e205ebb81 100644
--- a/phpBB/phpbb/db/driver/sqlite.php
+++ b/phpBB/phpbb/db/driver/sqlite.php
@@ -70,13 +70,16 @@ class sqlite extends \phpbb\db\driver\driver
 		if (!$use_cache || empty($cache) || ($this->sql_server_version = $cache->get('sqlite_version')) === false)
 		{
 			$result = @sqlite_query('SELECT sqlite_version() AS version', $this->db_connect_id);
-			$row = @sqlite_fetch_array($result, SQLITE_ASSOC);
+			if ($result)
+			{
+				$row = sqlite_fetch_array($result, SQLITE_ASSOC);
 
-			$this->sql_server_version = (!empty($row['version'])) ? $row['version'] : 0;
+				$this->sql_server_version = (!empty($row['version'])) ? $row['version'] : 0;
 
-			if (!empty($cache) && $use_cache)
-			{
-				$cache->put('sqlite_version', $this->sql_server_version);
+				if (!empty($cache) && $use_cache)
+				{
+					$cache->put('sqlite_version', $this->sql_server_version);
+				}
 			}
 		}
 
@@ -145,14 +148,14 @@ class sqlite extends \phpbb\db\driver\driver
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
-				if ($cache && $cache_ttl)
+				if (!$this->query_result)
 				{
-					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
+					return false;
 				}
-				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
+
+				if ($cache && $cache_ttl)
 				{
-					$this->open_queries[(int) $this->query_result] = $this->query_result;
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 			}
 			else if (defined('DEBUG'))
@@ -211,7 +214,7 @@ class sqlite extends \phpbb\db\driver\driver
 			return $cache->sql_fetchrow($query_id);
 		}
 
-		return ($query_id !== false) ? @sqlite_fetch_array($query_id, SQLITE_ASSOC) : false;
+		return ($query_id) ? sqlite_fetch_array($query_id, SQLITE_ASSOC) : false;
 	}
 
 	/**
@@ -231,7 +234,7 @@ class sqlite extends \phpbb\db\driver\driver
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
 
-		return ($query_id !== false) ? @sqlite_seek($query_id, $rownum) : false;
+		return ($query_id) ? @sqlite_seek($query_id, $rownum) : false;
 	}
 
 	/**
@@ -362,9 +365,12 @@ class sqlite extends \phpbb\db\driver\driver
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = @sqlite_query($query, $this->db_connect_id);
-				while ($void = @sqlite_fetch_array($result, SQLITE_ASSOC))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+					while ($void = sqlite_fetch_array($result, SQLITE_ASSOC))
+					{
+						// Take the time spent on parsing rows into account
+					}
 				}
 
 				$splittime = explode(' ', microtime());
diff --git a/phpBB/phpbb/db/driver/sqlite3.php b/phpBB/phpbb/db/driver/sqlite3.php
index 4e3e0d3329..f5c2dd225b 100644
--- a/phpBB/phpbb/db/driver/sqlite3.php
+++ b/phpBB/phpbb/db/driver/sqlite3.php
@@ -147,6 +147,11 @@ class sqlite3 extends \phpbb\db\driver\driver
 					$this->sql_time += microtime(true) - $this->curtime;
 				}
 
+				if (!$this->query_result)
+				{
+					return false;
+				}
+
 				if ($cache && $cache_ttl)
 				{
 					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
@@ -388,9 +393,12 @@ class sqlite3 extends \phpbb\db\driver\driver
 				$endtime = $endtime[0] + $endtime[1];
 
 				$result = $this->dbo->query($query);
-				while ($void = $result->fetchArray(SQLITE3_ASSOC))
+				if ($result)
 				{
-					// Take the time spent on parsing rows into account
+						while ($void = $result->fetchArray(SQLITE3_ASSOC))
+						{
+							// Take the time spent on parsing rows into account
+						}
 				}
 
 				$splittime = explode(' ', microtime());