After merge fixes

mysql-test/r/alter_table.result:
  Fixed results after merge
sql/handler.cc:
  Trivial optimzation
sql/sql_table.cc:
  Trvial optimization
sql/sql_yacc.yy:
  After merge fix
sql/unireg.cc:
  Removed argument 'null_fields' from make_empty_rec() as it was not needed
  Moved assert() to right place to take bit fields into account

mysql-test/r/alter_table.result

@@ -389,7 +389,7 @@ alter table t1 modify a varchar(10);
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `a` varchar(10) NOT NULL default '',
+  `a` varchar(10) NOT NULL,
   PRIMARY KEY  (`a`)
 ) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`)
 flush tables;
@@ -397,7 +397,7 @@ alter table t1 modify a varchar(10) not null;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `a` varchar(10) NOT NULL default '',
+  `a` varchar(10) NOT NULL,
   PRIMARY KEY  (`a`)
 ) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`)
 drop table if exists t1, t2;
@@ -405,17 +405,26 @@ create table t1 (a int, b int, c int, d int, e int, f int, g int, h int,i int, p
 insert into t1 (a) values(1);
 show table status like 't1';
 Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
-t1	MyISAM	9	Fixed	1	37	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
+t1	MyISAM	10	Fixed	1	37	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
 alter table t1 modify a int;
 show table status like 't1';
 Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
-t1	MyISAM	9	Fixed	1	37	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
+t1	MyISAM	10	Fixed	1	37	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
 drop table t1;
 create table t1 (a int not null, b int not null, c int not null, d int not null, e int not null, f int not null, g int not null, h int not null,i int not null, primary key (a,b,c,d,e,f,g,i,h)) engine=MyISAM;
 insert into t1 (a) values(1);
+Warnings:
+Warning	1364	Field 'b' doesn't have a default value
+Warning	1364	Field 'c' doesn't have a default value
+Warning	1364	Field 'd' doesn't have a default value
+Warning	1364	Field 'e' doesn't have a default value
+Warning	1364	Field 'f' doesn't have a default value
+Warning	1364	Field 'g' doesn't have a default value
+Warning	1364	Field 'h' doesn't have a default value
+Warning	1364	Field 'i' doesn't have a default value
 show table status like 't1';
 Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
-t1	MyISAM	9	Fixed	1	37	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
+t1	MyISAM	10	Fixed	1	37	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
 drop table t1;
 set names koi8r;
 create table t1 (a char(10) character set koi8r);

sql/handler.cc

@@ -1420,6 +1420,7 @@ void handler::update_auto_increment()
   ulonglong nr;
   THD *thd= table->in_use;
   struct system_variables *variables= &thd->variables;
+  bool auto_increment_field_not_null;
   DBUG_ENTER("handler::update_auto_increment");
 
   /*
@@ -1427,13 +1428,14 @@ void handler::update_auto_increment()
     row was not inserted
   */
   thd->prev_insert_id= thd->next_insert_id;
+  auto_increment_field_not_null= table->auto_increment_field_not_null;
+  table->auto_increment_field_not_null= FALSE;
 
   if ((nr= table->next_number_field->val_int()) != 0 ||
-      table->auto_increment_field_not_null &&
+      auto_increment_field_not_null &&
       thd->variables.sql_mode & MODE_NO_AUTO_VALUE_ON_ZERO)
   {
     /* Clear flag for next row */
-    table->auto_increment_field_not_null= FALSE;
     /* Mark that we didn't generate a new value **/
     auto_increment_column_changed=0;
 
@@ -1449,7 +1451,6 @@ void handler::update_auto_increment()
     }
     DBUG_VOID_RETURN;
   }
-  table->auto_increment_field_not_null= FALSE;
   if (!(nr= thd->next_insert_id))
   {
     nr= get_auto_increment();

sql/sql_table.cc

@@ -640,7 +640,7 @@ static int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
 {
   const char	*key_name;
   create_field	*sql_field,*dup_field;
-  uint		field,null_fields,blob_columns;
+  uint		field,null_fields,blob_columns,max_key_length;
   ulong		record_offset= 0;
   KEY		*key_info;
   KEY_PART_INFO *key_part_info;
@@ -654,6 +654,7 @@ static int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
   select_field_pos= fields->elements - select_field_count;
   null_fields=blob_columns=0;
   create_info->varchar= 0;
+  max_key_length= file->max_key_length();
 
   for (field_no=0; (sql_field=it++) ; field_no++)
   {
@@ -1190,10 +1191,10 @@ static int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
       {
 	if (f_is_blob(sql_field->pack_flag))
 	{
-	  if ((length=column->length) > file->max_key_length() ||
+	  if ((length=column->length) > max_key_length ||
 	      length > file->max_key_part_length())
 	  {
-	    length=min(file->max_key_length(), file->max_key_part_length());
+	    length=min(max_key_length, file->max_key_part_length());
 	    if (key->type == Key::MULTIPLE)
 	    {
 	      /* not a critical problem */

sql/sql_yacc.yy

@@ -3990,7 +3990,7 @@ select_options:
 	  {
 	    if (test_all_bits(Select->options, SELECT_ALL | SELECT_DISTINCT))
 	    {
-	      net_printf(Lex->thd, ER_WRONG_USAGE, "ALL", "DISTINCT");
+	      my_error(ER_WRONG_USAGE, MYF(0), "ALL", "DISTINCT");
               YYABORT;
 	    }
           }

sql/unireg.cc

@@ -45,8 +45,7 @@ static bool pack_fields(File file, List<create_field> &create_fields,
 static bool make_empty_rec(THD *thd, int file, enum db_type table_type,
 			   uint table_options,
 			   List<create_field> &create_fields,
-			   uint reclength, uint null_fields,
-                           ulong data_offset);
+			   uint reclength, ulong data_offset);
 
 /*
   Create a frm (table definition) file
@@ -72,7 +71,7 @@ bool mysql_create_frm(THD *thd, my_string file_name,
 		      uint keys, KEY *key_info,
 		      handler *db_file)
 {
-  uint reclength,info_length,screens,key_info_length,maxlength,null_fields;
+  uint reclength,info_length,screens,key_info_length,maxlength;
   File file;
   ulong filepos, data_offset;
   uchar fileinfo[64],forminfo[288],*keybuff;
@@ -111,7 +110,6 @@ bool mysql_create_frm(THD *thd, my_string file_name,
     }
   }
   reclength=uint2korr(forminfo+266);
-  null_fields=uint2korr(forminfo+282);
 
   if ((file=create_frm(file_name, reclength, fileinfo,
 		       create_info, keys)) < 0)
@@ -145,7 +143,7 @@ bool mysql_create_frm(THD *thd, my_string file_name,
 	       (ulong) uint2korr(fileinfo+6)+ (ulong) key_buff_length,
 	       MY_SEEK_SET,MYF(0)));
   if (make_empty_rec(thd,file,create_info->db_type,create_info->table_options,
-		     create_fields,reclength, null_fields, data_offset))
+		     create_fields,reclength, data_offset))
     goto err;
 
   VOID(my_seek(file,filepos,MY_SEEK_SET,MYF(0)));
@@ -661,7 +659,7 @@ static bool pack_fields(File file, List<create_field> &create_fields,
 static bool make_empty_rec(THD *thd, File file,enum db_type table_type,
 			   uint table_options,
 			   List<create_field> &create_fields,
-			   uint reclength, uint null_fields,
+			   uint reclength,
                            ulong data_offset)
 {
   int error;
@@ -696,7 +694,6 @@ static bool make_empty_rec(THD *thd, File file,enum db_type table_type,
     null_count++;			// Need one bit for delete mark
     *buff|= 1;
   }
-  DBUG_ASSERT(data_offset == ((null_fields + null_count + 7) / 8));
   null_pos= buff;
 
   List_iterator<create_field> it(create_fields);
@@ -756,6 +753,7 @@ static bool make_empty_rec(THD *thd, File file,enum db_type table_type,
     else
       regfield->reset();
   }
+  DBUG_ASSERT(data_offset == ((null_count + 7) / 8));
 
   /* Fill not used startpos */
   if (null_count)