diff --git a/storage/xtradb/log/log0log.cc b/storage/xtradb/log/log0log.cc
index e0b378cd98b..7783fc1ac13 100644
--- a/storage/xtradb/log/log0log.cc
+++ b/storage/xtradb/log/log0log.cc
@@ -30,6 +30,13 @@ Database log
 Created 12/9/1995 Heikki Tuuri
 *******************************************************/
 
+#include "config.h"
+#ifdef HAVE_ALLOCA_H
+#include "alloca.h"
+#elif defined(HAVE_MALLOC_H) 
+#include "malloc.h"
+#endif
+
 #include "log0log.h"
 
 #ifdef UNIV_NONINL
@@ -246,7 +253,7 @@ log_buffer_extend(
 {
 	ulint	move_start;
 	ulint	move_end;
-	byte	tmp_buf[OS_FILE_LOG_BLOCK_SIZE];
+	byte	*tmp_buf = (byte*)alloca(OS_FILE_LOG_BLOCK_SIZE);
 
 	mutex_enter(&(log_sys->mutex));
 
diff --git a/storage/xtradb/log/log0online.cc b/storage/xtradb/log/log0online.cc
index 2e66a690fea..127e09e0448 100644
--- a/storage/xtradb/log/log0online.cc
+++ b/storage/xtradb/log/log0online.cc
@@ -34,14 +34,6 @@ Online database log parsing for changed page tracking
 #include "trx0sys.h"
 #include "ut0rbt.h"
 
-#ifdef __WIN__
-/* error LNK2001: unresolved external symbol _debug_sync_C_callback_ptr */
-# define DEBUG_SYNC_C(dummy) ((void) 0)
-#else
-# include "m_string.h" /* for my_sys.h */
-# include "my_sys.h" /* DEBUG_SYNC_C */
-#endif
-
 enum { FOLLOW_SCAN_SIZE = 4 * (UNIV_PAGE_SIZE_MAX) };
 
 #ifdef UNIV_PFS_MUTEX