Portablity fixes & simple optimizations

sql/ha_ndbcluster.cc:
  Added missing cast
sql/item.cc:
  Portability fix (for windows)
sql/lock.cc:
  Cleanup + more comments
sql/sql_class.cc:
  Portability fix + more comments
sql/sql_select.cc:
  Portability fix
sql/sql_table.cc:
  Simpler handling of auto_increment in ALTER TABLE

sql/ha_ndbcluster.cc

@@ -1423,7 +1423,8 @@ int ha_ndbcluster::write_row(byte *record)
   {
     Uint64 next_val= (Uint64) table->next_number_field->val_int() + 1;
     DBUG_PRINT("info", 
-	       ("Trying to set next auto increment value to %u", next_val));
+	       ("Trying to set next auto increment value to %lu",
+                (ulong) next_val));
     if (m_ndb->setAutoIncrementValue((NDBTAB *) m_table, next_val, true))
       DBUG_PRINT("info", 
 		 ("Setting next auto increment value to %u", next_val));  

sql/item.cc

@@ -919,7 +919,7 @@ double Item_param::val()
       This works for example when user says SELECT ?+0.0 and supplies
       time value for the placeholder.
     */
-    return (double) TIME_to_ulonglong(&value.time);
+    return ulonglong2double(TIME_to_ulonglong(&value.time));
   case NULL_VALUE:
     return 0.0;
   default:

sql/lock.cc

@@ -787,7 +787,7 @@ bool wait_if_global_read_lock(THD *thd, bool abort_on_refresh, bool is_not_commi
 
   LINT_INIT(old_message);
   (void) pthread_mutex_lock(&LOCK_open);
-  if (need_exit_cond= must_wait)
+  if ((need_exit_cond= must_wait))
   {
     if (thd->global_read_lock)		// This thread had the read locks
     {
@@ -805,7 +805,11 @@ bool wait_if_global_read_lock(THD *thd, bool abort_on_refresh, bool is_not_commi
   }
   if (!abort_on_refresh && !result)
     protect_against_global_read_lock++;
-  if (unlikely(need_exit_cond)) // global read locks are rare
+  /*
+    The following is only true in case of a global read locks (which is rare)
+    and if old_message is set
+  */
+  if (unlikely(need_exit_cond)) 
     thd->exit_cond(old_message);
   else
     pthread_mutex_unlock(&LOCK_open);

sql/sql_class.cc

@@ -155,11 +155,13 @@ bool foreign_key_prefix(Key *a, Key *b)
 ** Thread specific functions
 ****************************************************************************/
 
-THD::THD():user_time(0), current_arena(this), is_fatal_error(0),
-	   last_insert_id_used(0),
-           insert_id_used(0), rand_used(0), time_zone_used(0),
-           in_lock_tables(0), global_read_lock(0), bootstrap(0)
+THD::THD()
+  :user_time(0), global_read_lock(0), is_fatal_error(0),
+   last_insert_id_used(0),
+   insert_id_used(0), rand_used(0), time_zone_used(0),
+   in_lock_tables(0), bootstrap(0)
 {
+  current_arena= this;
   host= user= priv_user= db= ip=0;
   host_or_ip= "connecting host";
   locked=some_tables_deleted=no_errors=password= 0;
@@ -439,10 +441,13 @@ void THD::awake(bool prepare_to_die)
       it is the true value but maybe current_mutex is not yet non-zero (we're
       in the middle of enter_cond() and there is a "memory order
       inversion"). So we test the mutex too to not lock 0.
+
       Note that there is a small chance we fail to kill. If victim has locked
-      current_mutex, and hasn't entered enter_cond(), then we don't know it's
-      going to wait on cond. Then victim goes into its cond "forever" (until
-      we issue a second KILL). True we have set its thd->killed but it may not
+      current_mutex, but hasn't yet entered enter_cond() (which means that
+      current_cond and current_mutex are 0), then the victim will not get
+      a signal and it may wait "forever" on the cond (until
+      we issue a second KILL or the status it's waiting for happens).
+      It's true that we have set its thd->killed but it may not
       see it immediately and so may have time to reach the cond_wait().
     */
     if (mysys_var->current_cond && mysys_var->current_mutex)

sql/sql_select.cc

@@ -8014,7 +8014,7 @@ find_order_in_list(THD *thd, Item **ref_pointer_array,
   Item *itemptr=*order->item;
   if (itemptr->type() == Item::INT_ITEM)
   {						/* Order by position */
-    uint count= itemptr->val_int();
+    uint count= (uint) itemptr->val_int();
     if (!count || count > fields.elements)
     {
       my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),

sql/sql_table.cc

@@ -3281,7 +3281,7 @@ copy_data_between_tables(TABLE *from,TABLE *to,
 			 ha_rows *deleted)
 {
   int error;
-  Copy_field *copy,*copy_end, *next_field= 0;
+  Copy_field *copy,*copy_end;
   ulong found_count,delete_count;
   THD *thd= current_thd;
   uint length;
@@ -3291,6 +3291,7 @@ copy_data_between_tables(TABLE *from,TABLE *to,
   List<Item>   fields;
   List<Item>   all_fields;
   ha_rows examined_rows;
+  bool auto_increment_field_copied= 0;
   DBUG_ENTER("copy_data_between_tables");
 
   if (!(copy= new Copy_field[to->fields]))
@@ -3309,7 +3310,7 @@ copy_data_between_tables(TABLE *from,TABLE *to,
     if (def->field)
     {
       if (*ptr == to->next_number_field)
-        next_field= copy_end;
+        auto_increment_field_copied= TRUE;
       (copy_end++)->set(*ptr,def->field,0);
     }
 
@@ -3368,11 +3369,14 @@ copy_data_between_tables(TABLE *from,TABLE *to,
     }
     thd->row_count++;
     if (to->next_number_field)
-      to->next_number_field->reset();
-    for (Copy_field *copy_ptr=copy ; copy_ptr != copy_end ; copy_ptr++)
     {
-      if (copy_ptr == next_field)
+      if (auto_increment_field_copied)
         to->auto_increment_field_not_null= TRUE;
+      else
+        to->next_number_field->reset();
+    }
+    for (Copy_field *copy_ptr=copy ; copy_ptr != copy_end ; copy_ptr++)
+    {
       copy_ptr->do_copy(copy_ptr);
     }
     if ((error=to->file->write_row((byte*) to->record[0])))