From 437a5d90b227921f84ce9b9ed11047b27ed09f17 Mon Sep 17 00:00:00 2001
From: Machiavelli <none@none>
Date: Sun, 16 May 2010 13:31:52 +0200
Subject: [PATCH] Fix a possible crash in SqlTransaction::Execute(), using
 post-iterating on the LockedQueue instead of pre-iterating. Thanks to click
 for the insight and Spp for testing.

--HG--
branch : trunk
---
 src/shared/Database/SqlOperations.cpp | 15 +++++++++++++--
 src/shared/LockedQueue.h              | 15 ++++++++++++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/shared/Database/SqlOperations.cpp b/src/shared/Database/SqlOperations.cpp
index c766d6ca21d..8894f896855 100644
--- a/src/shared/Database/SqlOperations.cpp
+++ b/src/shared/Database/SqlOperations.cpp
@@ -35,21 +35,32 @@ void SqlTransaction::Execute(Database *db)
 {
     const char* sql;
 
+    if (m_queue.empty())
+        return;
+
     db->DirectExecute("START TRANSACTION");
-    while (m_queue.next(sql))
+    while (!m_queue.empty())
     {
+        sql = m_queue.peek();
+        m_queue.unlock();
         if (!db->DirectExecute(sql))
         {
             free((void*)const_cast<char*>(sql));
+            m_queue.pop_front();
             db->DirectExecute("ROLLBACK");
-            while (m_queue.next(sql))
+            while (!m_queue.empty())
             {
+                sql = m_queue.peek();
+                m_queue.unlock();
                 free((void*)const_cast<char*>(sql));
+                m_queue.pop_front();
             }
+            
             return;
         }
 
         free((void*)const_cast<char*>(sql));
+        m_queue.pop_front();
     }
 
     db->DirectExecute("COMMIT");
diff --git a/src/shared/LockedQueue.h b/src/shared/LockedQueue.h
index fd0a0d5d22d..9f8afae6c14 100644
--- a/src/shared/LockedQueue.h
+++ b/src/shared/LockedQueue.h
@@ -87,7 +87,6 @@ namespace ACE_Based
             {
                 lock();
 
-
                 T& result = _queue.front();
 
                 return result;
@@ -121,6 +120,20 @@ namespace ACE_Based
             {
                 this->_lock.release();
             }
+            
+            ///! Calls pop_front of the queue
+            void pop_front()
+            {
+                ACE_GUARD (LockType, g, this->_lock);
+                _queue.pop_front();
+            }
+            
+            ///! Checks if we're empty or not with locks held
+            bool empty()
+            {
+                ACE_GUARD_RETURN (LockType, g, this->_lock, false);
+                return _queue.empty();
+            }
     };
 }
 #endif