Merge lp:~laurynas-biveinis/percona-server/bug902472 into lp:percona-server/5.1

[Laurynas Biveinis]

Fix bug 902472 (main.subselect_notembedded fails on Ubuntu Oneiric in
Jenkins) and upstream bug http://bugs.mysql.com/bug.php?id=62856.

The issue is the Autoconf stack direction test, which relies on
the undefined behaviour and compilers not optimizing the test too
much. Adjust the test to work with GCC 4.6 by taking the contributed
patch from the upstream bug, which in turn is the 5.5 test backported
from CMake to Autoconf.

Jenkins: http://jenkins.percona.com/job/percona-server-5.1-param/389/

5.5 already contains the correct test, thus should be null-merged to 5.5

[Stewart Smith (stewart)]

review: Approve

=== modified file 'Percona-Server/config/ac-macros/misc.m4'
--- Percona-Server/config/ac-macros/misc.m4	2009-11-04 23:08:21 +0000
+++ Percona-Server/config/ac-macros/misc.m4	2012-08-25 10:32:21 +0000
@@ -460,22 +460,22 @@
 #if defined(__HP_cc) || defined (__HP_aCC) || defined (__hpux)
 #pragma noinline
 #endif
- int find_stack_direction ()
- {
-   static char *addr = 0;
-   auto char dummy;
-   if (addr == 0)
-     {
-       addr = &dummy;
-       return find_stack_direction ();
-     }
-   else
-     return (&dummy > addr) ? 1 : -1;
- }
- int main ()
- {
-   exit (find_stack_direction() < 0);
- }], ac_cv_c_stack_direction=1, ac_cv_c_stack_direction=-1,
+/* Check stack direction (0-down, 1-up) */
+int f(int *a) 
+{
+  int b;
+  return(&b > a)?1:-1; 
+}
+/*
+ Prevent compiler optimizations by calling function 
+ through pointer.
+*/
+volatile int (*ptr_f)(int *) = f;
+int main() 
+{
+  int a;
+  exit(ptr_f(&a) < 0);
+}], ac_cv_c_stack_direction=1, ac_cv_c_stack_direction=-1,
    ac_cv_c_stack_direction=)])
  AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction)
 ])dnl