rollback current transaction before trying to report SQL query errors, properly save database error messages when logging query errors

classes/db/mysql.php

@@ -26,9 +26,12 @@ class Db_Mysql implements IDb {
 	}
 
 	function query($query, $die_on_error = true) {
-		$result = mysql_query($query, $this->link);
+		$result = @mysql_query($query, $this->link);
 		if (!$result) {
-			user_error("Query $query failed: " . ($this->link ? mysql_error($this->link) : "No connection"),
+			$error = @mysql_error($this->link);
+
+			@mysql_query("ROLLBACK", $this->link);
+			user_error("Query $query failed: " . ($this->link ? $error : "No connection"),
 				$die_on_error ? E_USER_ERROR : E_USER_WARNING);
 		}
 		return $result;

classes/db/mysqli.php

@@ -24,9 +24,12 @@ class Db_Mysqli implements IDb {
 	}
 
 	function query($query, $die_on_error = true) {
-		$result = mysqli_query($this->link, $query);
+		$result = @mysqli_query($this->link, $query);
 		if (!$result) {
-			user_error("Query $query failed: " . ($this->link ? mysqli_error($this->link) : "No connection"),
+			$error = @mysqli_error($this->link);
+
+			@mysqli_query($this->link, "ROLLBACK");
+			user_error("Query $query failed: " . ($this->link ? $error : "No connection"),
 				$die_on_error ? E_USER_ERROR : E_USER_WARNING);
 		}
 

classes/db/pgsql.php

@@ -35,11 +35,14 @@ class Db_Pgsql implements IDb {
 	}
 
 	function query($query, $die_on_error = true) {
-		$result = pg_query($query);
+		$result = @pg_query($this->link, $query);
 
 		if (!$result) {
+			$error = @pg_last_error($this->link);
+
+			@pg_query($this->link, "ROLLBACK");
 			$query = htmlspecialchars($query); // just in case
-			user_error("Query $query failed: " . ($this->link ? pg_last_error($this->link) : "No connection"),
+			user_error("Query $query failed: " . ($this->link ? $error : "No connection"),
 				$die_on_error ? E_USER_ERROR : E_USER_WARNING);
 		}
 		return $result;