Fixed many compiler warnings

Fixed bugs in group_concat with ORDER BY and DISTINCT (Bugs #2695, #3381 and #3319)
Fixed crash when doing rollback in slave and the io thread catched up with the sql thread
Set locked_in_memory properly


include/mysql_com.h:
  Fixed compiler warning
libmysqld/emb_qcache.cc:
  Removed not used variable
libmysqld/lib_sql.cc:
  Removed not used variable
myisam/mi_locking.c:
  Added comment
myisam/mi_rnext.c:
  Fixed bug in concurrent insert
myisam/mi_rprev.c:
  Simple optimization
mysql-test/r/func_gconcat.result:
  New tests
mysql-test/t/func_gconcat.test:
  New tests
mysql-test/t/func_group.test:
  Cleanup
sql-common/client.c:
  Removed compiler warning
sql/derror.cc:
  Better comments
sql/field.cc:
  Removed not used function/variable
sql/field.h:
  Removed not needed variable
sql/ha_innodb.cc:
  Removed not used function
sql/item.cc:
  Fixed compiler warning
sql/item_cmpfunc.cc:
  Fixed compiler warning
sql/item_func.cc:
  Fixed compiler warning
sql/item_geofunc.cc:
  Fixed compiler warning
sql/item_sum.cc:
  Fixed bugs in group_concat and added more comments
  (Bugs #2695, #3381 and #3319)
  - field->abs_offset was not needed
  - Wrong assumption of field order in temporary table
  - Some not used variables removed
  - Added ORDER BY fields after argument fields so that code in sql_select.cc can move all fields to point to temporary tables, if needed.
  - Optimized loops
sql/item_sum.h:
  Bug fixing and cleanup of group_concat()
sql/log.cc:
  Removed wrong comment
sql/log_event.cc:
  Removed compiler warning
sql/mysqld.cc:
  Set locked_in_memory properly
sql/protocol.cc:
  Removed compiler warning
sql/set_var.cc:
  Code cleanup
sql/slave.cc:
  Fixed crash when doing rollback in slave and the io thread catched up with the sql thread
sql/sql_cache.cc:
  Removed compiler warnings
sql/sql_derived.cc:
  Removed not used variable
sql/sql_insert.cc:
  Removed compiler warnings
sql/sql_lex.cc:
  Removed not used lable
sql/sql_lex.h:
  Removed compiler warnings
sql/sql_parse.cc:
  Removed compiler warnings
sql/sql_prepare.cc:
  Removed compiler warnings
sql/sql_select.cc:
  Removed not used variables
  Added function comments
sql/sql_show.cc:
  Removed compiler warnings
sql/sql_yacc.yy:
  Fix for ORDER BY handling in GROUP_CONCAT()

sql/sql_parse.cc

@@ -48,7 +48,9 @@
 extern "C" int gethostname(char *name, int namelen);
 #endif
 
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
 static int check_for_max_user_connections(THD *thd, USER_CONN *uc);
+#endif
 static void decrease_user_connections(USER_CONN *uc);
 static bool check_db_used(THD *thd,TABLE_LIST *tables);
 static bool check_merge_table_access(THD *thd, char *db, TABLE_LIST *tables);
@@ -426,6 +428,8 @@ void init_max_user_conn(void)
     1	error
 */
 
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+
 static int check_for_max_user_connections(THD *thd, USER_CONN *uc)
 {
   int error=0;
@@ -456,7 +460,7 @@ static int check_for_max_user_connections(THD *thd, USER_CONN *uc)
   (void) pthread_mutex_unlock(&LOCK_user_conn);
   DBUG_RETURN(error);
 }
-
+#endif /* NO_EMBEDDED_ACCESS_CHECKS */
 
 /*
   Decrease user connection count
@@ -545,15 +549,15 @@ bool is_update_query(enum enum_sql_command command)
 
 static bool check_mqh(THD *thd, uint check_command)
 {
+#ifdef NO_EMBEDDED_ACCESS_CHECKS
+  return(0);
+#else
   bool error=0;
   time_t check_time = thd->start_time ?  thd->start_time : time(NULL);
   USER_CONN *uc=thd->user_connect;
   DBUG_ENTER("check_mqh");
   DBUG_ASSERT(uc != 0);
 
-#ifdef NO_EMBEDDED_ACCESS_CHECKS
-  DBUG_RETURN(0);
-#else
   /* If more than a hour since last check, reset resource checking */
   if (check_time  - uc->intime >= 3600)
   {
@@ -3518,7 +3522,10 @@ check_access(THD *thd, ulong want_access, const char *db, ulong *save_priv,
   DBUG_ENTER("check_access");
   DBUG_PRINT("enter",("want_access: %lu  master_access: %lu", want_access,
 		      thd->master_access));
-  ulong db_access,dummy;
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  ulong db_access;
+#endif
+  ulong dummy;
   if (save_priv)
     *save_priv=0;
   else