From 5826dd061e333b7393ff35e02d10907a43cbec08 Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Mon, 15 Dec 2014 16:56:35 +0100
Subject: [PATCH] Overhauled error handling in Database classes

Since we're no longer using prepared statement emulation, prepares fail at another stage which did not properly report the actual error message.

Additionally I've changed the error mode to actually throw exceptions rather than bogus non-success return values like 'false'.
---
 .../files/lib/system/database/Database.class.php | 16 +++++++---------
 .../system/database/DatabaseException.class.php  | 15 +++++++++++++--
 .../lib/system/database/MySQLDatabase.class.php  |  3 +++
 3 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/wcfsetup/install/files/lib/system/database/Database.class.php b/wcfsetup/install/files/lib/system/database/Database.class.php
index 5ef87d8e0d..e8f727ea2d 100644
--- a/wcfsetup/install/files/lib/system/database/Database.class.php
+++ b/wcfsetup/install/files/lib/system/database/Database.class.php
@@ -124,7 +124,7 @@ abstract class Database {
 			return $this->pdo->lastInsertId();
 		}
 		catch (\PDOException $e) {
-			throw new DatabaseException("Cannot fetch last insert id", $this);
+			throw new DatabaseException("Cannot fetch last insert id: " . $e->getMessage(), $this);
 		}
 	}
 	
@@ -150,7 +150,7 @@ abstract class Database {
 			return $result;
 		}
 		catch (\PDOException $e) {
-			throw new DatabaseException("Cannot begin transaction", $this);
+			throw new DatabaseException("Cannot begin transaction: " . $e->getMessage(), $this);
 		}
 	}
 	
@@ -179,7 +179,7 @@ abstract class Database {
 			return $result;
 		}
 		catch (\PDOException $e) {
-			throw new DatabaseException("Cannot commit transaction", $this);
+			throw new DatabaseException("Cannot commit transaction: " . $e->getMessage(), $this);
 		}
 	}
 	
@@ -207,7 +207,7 @@ abstract class Database {
 			return $result;
 		}
 		catch (\PDOException $e) {
-			throw new DatabaseException("Cannot rollback transaction", $this);
+			throw new DatabaseException("Cannot rollback transaction: " . $e->getMessage(), $this);
 		}
 	}
 	
@@ -224,13 +224,11 @@ abstract class Database {
 		
 		try {
 			$pdoStatement = $this->pdo->prepare($statement);
-			if ($pdoStatement instanceof \PDOStatement) {
-				return new $this->preparedStatementClassName($this, $pdoStatement, $statement);
-			}
-			throw new DatabaseException("Cannot prepare statement: ".$statement, $this);
+			
+			return new $this->preparedStatementClassName($this, $pdoStatement, $statement);
 		}
 		catch (\PDOException $e) {
-			throw new DatabaseException("Cannot prepare statement: ".$statement, $this);
+			throw new DatabaseException($e->getMessage(), $this, null, $statement);
 		}
 	}
 	
diff --git a/wcfsetup/install/files/lib/system/database/DatabaseException.class.php b/wcfsetup/install/files/lib/system/database/DatabaseException.class.php
index 4a4c8372d2..ae44fa31a9 100644
--- a/wcfsetup/install/files/lib/system/database/DatabaseException.class.php
+++ b/wcfsetup/install/files/lib/system/database/DatabaseException.class.php
@@ -51,17 +51,25 @@ class DatabaseException extends SystemException {
 	 */
 	protected $preparedStatement = null;
 	
+	/**
+	 * SQL query if prepare() failed
+	 * @var	string
+	 */
+	protected $sqlQuery = null;
+	
 	/**
 	 * Creates a new DatabaseException.
 	 * 
 	 * @param	string							$message		error message
 	 * @param	\wcf\system\database\Database				$db			affected db object
-	 * @param	\wcf\system\database\statement\PreparedStatement		$preparedStatement	affected prepared statement
+	 * @param	\wcf\system\database\statement\PreparedStatement	$preparedStatement	affected prepared statement
+	 * @param	string							$sqlQuery		SQL query if prepare() failed
 	 */
-	public function __construct($message, Database $db, PreparedStatement $preparedStatement = null) {
+	public function __construct($message, Database $db, PreparedStatement $preparedStatement = null, $sqlQuery = null) {
 		$this->db = $db;
 		$this->DBType = $db->getDBType();
 		$this->preparedStatement = $preparedStatement;
+		$this->sqlQuery = $sqlQuery;
 		
 		// prefer errors from prepared statement
 		if ($this->preparedStatement !== null && $this->preparedStatement->getErrorNumber()) {
@@ -138,6 +146,9 @@ class DatabaseException extends SystemException {
 				}
 			}
 		}
+		else if ($this->sqlQuery !== null) {
+			$this->information .= '<b>sql query:</b> ' . StringUtil::encodeHTML($this->sqlQuery) . '<br />';
+		}
 		
 		parent::show();
 	}
diff --git a/wcfsetup/install/files/lib/system/database/MySQLDatabase.class.php b/wcfsetup/install/files/lib/system/database/MySQLDatabase.class.php
index 8dc49a7135..fbd38893e7 100644
--- a/wcfsetup/install/files/lib/system/database/MySQLDatabase.class.php
+++ b/wcfsetup/install/files/lib/system/database/MySQLDatabase.class.php
@@ -36,6 +36,9 @@ class MySQLDatabase extends Database {
 			// disable prepared statement emulation since MySQL 5.1.17 is the minimum required version
 			$driverOptions[\PDO::ATTR_EMULATE_PREPARES] = false;
 			
+			// throw PDOException instead of dumb false return values
+			$driverOptions[\PDO::ATTR_ERRMODE] = \PDO::ERRMODE_EXCEPTION;
+			
 			$this->pdo = new \PDO('mysql:host='.$this->host.';port='.$this->port.';dbname='.$this->database, $this->user, $this->password, $driverOptions);
 			$this->setAttributes();
 		}
-- 
2.20.1