Fix for bug #31207: Test "join_nested" shows different strategy on IA64

CPUs / Intel's ICC compile

The bug is a combination of two problems:

1. IA64/ICC MySQL binaries use glibc's qsort(), not the one in mysys.

2. The order relation implemented by join_tab_cmp() is not transitive,
i.e. it is possible to choose such a, b and c that (a < b) && (b < c)
but (c < a). This implies that result of a sort using the relation
implemented by join_tab_cmp() depends on the order in which
elements are compared, i.e. the result is implementation-specific. Since
choose_plan() uses qsort() to pre-sort the
join tables using join_tab_cmp() as a compare function, the results of
the sorting may vary depending on qsort() implementation.

It is neither possible nor important to implement a better ordering
algorithm in join_tab_cmp(). Therefore the only way to fix it is to
force our own qsort() to be used by renaming it to my_qsort(), so we don't depend
on linker to decide that.

This patch also "fixes" bug #20530: qsort redefinition violates the
standard.


include/my_sys.h:
  Renamed qsort() and qsort2() to my_qsort() and my_qsort2(). Since
  previously we relied on stdlib.h to provide a declaration for qsort(), a
  separate declaration for my_qsort() is now required.
libmysql/Makefile.shared:
  Added mf_qsort.c to libmysql, since my_lib.c now uses my_qsort() instead of qsort().
myisam/ft_boolean_search.c:
  Replaced qsort2() with my_qsort2().
myisam/ft_nlq_search.c:
  Replaced qsort2() with my_qsort2().
myisam/myisampack.c:
  Replaced qsort() with my_qsort().
myisam/sort.c:
  Replaced qsort2() with my_qsort2().
mysys/mf_keycache.c:
  Replaced qsort() with my_qsort().
mysys/mf_qsort.c:
  Renamed qsort() to my_qsort() and qsort2() to my_qsort2().
mysys/mf_sort.c:
  Replaced qsort2() with my_qsort2().
mysys/my_lib.c:
  Replaced qsort() with my_qsort().
mysys/queues.c:
  Replaced qsort2() with my_qsort2().
sql/item_cmpfunc.cc:
  Replaced qsort2() with my_qsort2().
sql/item_cmpfunc.h:
  Replaced qsort2() with my_qsort2().
sql/opt_range.cc:
  Replaced qsort() with my_qsort().
sql/records.cc:
  Replaced qsort() with my_qsort().
sql/sql_acl.cc:
  Replaced qsort() with my_qsort().
sql/sql_array.h:
  Replaced qsort() with my_qsort().
sql/sql_help.cc:
  Replaced qsort() with my_qsort().
sql/sql_select.cc:
  Replaced qsort() with my_qsort().
sql/examples/ha_tina.cc:
  Replaced qsort() with my_qsort().
sql/sql_table.cc:
  Replaced qsort() with my_qsort().

1 files changed, 10 insertions, 10 deletions

diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index f9bd2c6ba0d..d5257b1076a 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -248,8 +248,8 @@ static my_bool acl_load(THD *thd, TABLE_LIST *tables)
 #endif
     VOID(push_dynamic(&acl_hosts,(gptr) &host));
   }
-  qsort((gptr) dynamic_element(&acl_hosts,0,ACL_HOST*),acl_hosts.elements,
-	sizeof(ACL_HOST),(qsort_cmp) acl_compare);
+  my_qsort((gptr) dynamic_element(&acl_hosts,0,ACL_HOST*),acl_hosts.elements,
+           sizeof(ACL_HOST),(qsort_cmp) acl_compare);
   end_read_record(&read_record_info);
   freeze_size(&acl_hosts);
 
@@ -421,8 +421,8 @@ static my_bool acl_load(THD *thd, TABLE_LIST *tables)
         allow_all_hosts=1;			// Anyone can connect
     }
   }
-  qsort((gptr) dynamic_element(&acl_users,0,ACL_USER*),acl_users.elements,
-	sizeof(ACL_USER),(qsort_cmp) acl_compare);
+  my_qsort((gptr) dynamic_element(&acl_users,0,ACL_USER*),acl_users.elements,
+           sizeof(ACL_USER),(qsort_cmp) acl_compare);
   end_read_record(&read_record_info);
   freeze_size(&acl_users);
 
@@ -479,8 +479,8 @@ static my_bool acl_load(THD *thd, TABLE_LIST *tables)
 #endif
     VOID(push_dynamic(&acl_dbs,(gptr) &db));
   }
-  qsort((gptr) dynamic_element(&acl_dbs,0,ACL_DB*),acl_dbs.elements,
-	sizeof(ACL_DB),(qsort_cmp) acl_compare);
+  my_qsort((gptr) dynamic_element(&acl_dbs,0,ACL_DB*),acl_dbs.elements,
+           sizeof(ACL_DB),(qsort_cmp) acl_compare);
   end_read_record(&read_record_info);
   freeze_size(&acl_dbs);
   init_check_host();
@@ -1110,8 +1110,8 @@ static void acl_insert_user(const char *user, const char *host,
   if (!acl_user.host.hostname ||
       (acl_user.host.hostname[0] == wild_many && !acl_user.host.hostname[1]))
     allow_all_hosts=1;		// Anyone can connect /* purecov: tested */
-  qsort((gptr) dynamic_element(&acl_users,0,ACL_USER*),acl_users.elements,
-	sizeof(ACL_USER),(qsort_cmp) acl_compare);
+  my_qsort((gptr) dynamic_element(&acl_users,0,ACL_USER*),acl_users.elements,
+           sizeof(ACL_USER),(qsort_cmp) acl_compare);
 
   /* Rebuild 'acl_check_hosts' since 'acl_users' has been modified */
   rebuild_check_host();
@@ -1173,8 +1173,8 @@ static void acl_insert_db(const char *user, const char *host, const char *db,
   acl_db.access=privileges;
   acl_db.sort=get_sort(3,acl_db.host.hostname,acl_db.db,acl_db.user);
   VOID(push_dynamic(&acl_dbs,(gptr) &acl_db));
-  qsort((gptr) dynamic_element(&acl_dbs,0,ACL_DB*),acl_dbs.elements,
-	sizeof(ACL_DB),(qsort_cmp) acl_compare);
+  my_qsort((gptr) dynamic_element(&acl_dbs,0,ACL_DB*),acl_dbs.elements,
+           sizeof(ACL_DB),(qsort_cmp) acl_compare);
 }