sync0sync.c, sync0sync.h:

  Declare 'mutex_list' and 'mutex_list_mutex' extern,
  to avoid link error on OS X and gcc flag "-fno-common"


innobase/include/sync0sync.h:
  Use 'extern' variable declarations, to avoid
  "ld: multiple definitions of symbol" for 'mutex_list'
  and 'mutex_list_mutex' on OS X and gcc flag "-fno-common"
innobase/sync/sync0sync.c:
  Use 'extern' variable declarations, to avoid
  "ld: multiple definitions of symbol" for 'mutex_list'
  and 'mutex_list_mutex' on OS X and gcc flag "-fno-common"

innobase/include/sync0sync.h

@@ -522,10 +522,11 @@ extern ibool	sync_order_checks_on;
 extern ibool	sync_initialized;
 
 /* Global list of database mutexes (not OS mutexes) created. */
-UT_LIST_BASE_NODE_T(mutex_t)  mutex_list;
+typedef UT_LIST_BASE_NODE_T(mutex_t)  ut_list_base_node_t;
+extern ut_list_base_node_t  mutex_list;
 
 /* Mutex protecting the mutex_list variable */
-mutex_t mutex_list_mutex;
+extern mutex_t mutex_list_mutex;
 
 
 #ifndef UNIV_NONINL

innobase/sync/sync0sync.c

@@ -141,6 +141,12 @@ sync_thread_t*	sync_thread_level_arrays;
 /* Mutex protecting sync_thread_level_arrays */
 mutex_t	sync_thread_mutex;
 
+/* Global list of database mutexes (not OS mutexes) created. */
+ut_list_base_node_t  mutex_list;
+
+/* Mutex protecting the mutex_list variable */
+mutex_t mutex_list_mutex;
+
 /* Latching order checks start when this is set TRUE */
 ibool	sync_order_checks_on	= FALSE;