mysql.sln:

  Enable 'mysys' build if target 'Enterprise'
item_subselect.h:
  Fixed bug #27870. The bug that causes crashes manifests itself at some
  conditions when executing an equijoin query with WHERE condition
  containing a subquery predicate of the form join_attr NOT IN (SELECT ...).

VC++Files/mysql.sln

@@ -733,6 +733,7 @@ Global
 		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Debug 98.ActiveCfg = Debug 98|Win32
 		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Debug 98.Build.0 = Debug 98|Win32
 		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Enterprise.ActiveCfg = Release|Win32
+		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Enterprise.Build.0 = Release|Win32
 		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Enterprise Debug.ActiveCfg = Debug|Win32
 		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Enterprise Debug.Build.0 = Debug|Win32
 		{44D9C7DC-6636-4B82-BD01-6876C64017DF}.Enterprise GPL.ActiveCfg = Release|Win32

sql/item_subselect.h

@@ -276,7 +276,11 @@ public:
   {
     return pushed_cond_guards ? pushed_cond_guards + i : NULL;
   }
-  void set_cond_guard_var(int i, bool v) { pushed_cond_guards[i]= v; }
+  void set_cond_guard_var(int i, bool v) 
+  { 
+    if ( pushed_cond_guards)
+      pushed_cond_guards[i]= v;
+  }
   bool have_guarded_conds() { return test(pushed_cond_guards); }
 
   Item_func_not_all *upper_item; // point on NOT/NOP before ALL/SOME subquery