better fix BUG#2361: ALTER TABLE ... DROP PRIMARY KEY drops a non-primary key

mysql-test/r/alter_table.result

@@ -412,12 +412,15 @@ t1	0	PRIMARY	1	Host	A	NULL	NULL	NULL		BTREE
 t1	0	PRIMARY	2	User	A	0	NULL	NULL		BTREE	
 t1	1	Host	1	Host	A	NULL	NULL	NULL		BTREE	disabled
 DROP TABLE t1;
-CREATE TABLE t1 (a int UNIQUE);
+CREATE TABLE t1 (a int PRIMARY KEY, b INT UNIQUE);
 ALTER TABLE t1 DROP PRIMARY KEY;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` int(11) default NULL,
-  UNIQUE KEY `a` (`a`)
+  `a` int(11) NOT NULL default '0',
+  `b` int(11) default NULL,
+  UNIQUE KEY `b` (`b`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
+ALTER TABLE t1 DROP PRIMARY KEY;
+ERROR 42000: Can't DROP 'PRIMARY'. Check that column/key exists
 DROP TABLE t1;

mysql-test/t/alter_table.test

@@ -249,7 +249,9 @@ DROP TABLE t1;
 # Bug 2361
 #
 
-CREATE TABLE t1 (a int UNIQUE);
+CREATE TABLE t1 (a int PRIMARY KEY, b INT UNIQUE);
 ALTER TABLE t1 DROP PRIMARY KEY;
 SHOW CREATE TABLE t1;
+--error 1091
+ALTER TABLE t1 DROP PRIMARY KEY;
 DROP TABLE t1;

sql/mysql_priv.h

@@ -509,7 +509,6 @@ int mysql_alter_table(THD *thd, char *new_db, char *new_name,
 		      List<Key> &keys,List<Alter_drop> &drop_list,
 		      List<Alter_column> &alter_list,
                       uint order_num, ORDER *order,
-		      bool drop_primary,
 		      enum enum_duplicates handle_duplicates,
 		      enum enum_enable_or_disable keys_onoff=LEAVE_AS_IS,
 		      enum tablespace_op_type tablespace_op=NO_TABLESPACE_OP,

sql/sql_base.cc

@@ -2395,7 +2395,7 @@ int mysql_create_index(THD *thd, TABLE_LIST *table_list, List<Key> &keys)
   create_info.default_table_charset= thd->variables.collation_database;
   DBUG_RETURN(mysql_alter_table(thd,table_list->db,table_list->real_name,
 				&create_info, table_list,
-				fields, keys, drop, alter, 0, (ORDER*)0, FALSE,
+				fields, keys, drop, alter, 0, (ORDER*)0,
 				DUP_ERROR));
 }
 
@@ -2412,7 +2412,7 @@ int mysql_drop_index(THD *thd, TABLE_LIST *table_list, List<Alter_drop> &drop)
   create_info.default_table_charset= thd->variables.collation_database;
   DBUG_RETURN(mysql_alter_table(thd,table_list->db,table_list->real_name,
 				&create_info, table_list,
-				fields, keys, drop, alter, 0, (ORDER*)0, FALSE,
+				fields, keys, drop, alter, 0, (ORDER*)0,
 				DUP_ERROR));
 }
 

sql/sql_lex.h

@@ -575,7 +575,7 @@ typedef struct st_lex
   uint param_count;
   uint slave_thd_opt;
   uint8 describe;
-  bool drop_primary, drop_if_exists, drop_temporary, local_file;
+  bool drop_if_exists, drop_temporary, local_file;
   bool in_comment, ignore_space, verbose, simple_alter, no_write_to_binlog;
   bool derived_tables;
   bool safe_to_cache_query;

sql/sql_parse.cc

@@ -2319,7 +2319,7 @@ mysql_execute_command(THD *thd)
 			       lex->key_list, lex->drop_list, lex->alter_list,
 			       select_lex->order_list.elements,
                                (ORDER *) select_lex->order_list.first,
-			       lex->drop_primary, lex->duplicates,
+			       lex->duplicates,
 			       lex->alter_keys_onoff,
                                lex->tablespace_op,
 			       lex->simple_alter);
@@ -2466,7 +2466,7 @@ mysql_execute_command(THD *thd)
 			     tables, lex->create_list,
 			     lex->key_list, lex->drop_list, lex->alter_list,
                              0, (ORDER *) 0,
-			     0, DUP_ERROR);
+			     DUP_ERROR);
     }
     else
       res = mysql_optimize_table(thd, tables, &lex->check_opt);

sql/sql_table.cc

@@ -1962,7 +1962,6 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
 		      List<Key> &keys,List<Alter_drop> &drop_list,
 		      List<Alter_column> &alter_list,
                       uint order_num, ORDER *order,
-		      bool drop_primary,
 		      enum enum_duplicates handle_duplicates,
 	              enum enum_enable_or_disable keys_onoff,
 		      enum tablespace_op_type tablespace_op,
@@ -2171,7 +2170,7 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
     def_it.rewind();
     while ((def=def_it++))
     {
-      if (def->change && 
+      if (def->change &&
           !my_strcasecmp(system_charset_info,field->field_name, def->change))
 	break;
     }
@@ -2265,14 +2264,6 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
   for (uint i=0 ; i < table->keys ; i++,key_info++)
   {
     char *key_name= key_info->name;
-
-    if (drop_primary && (key_info-> flags & HA_NOSAME) &&
-	!my_strcasecmp(system_charset_info, key_name, primary_key_name))
-    {
-      drop_primary= 0;
-      continue;
-    }
-
     Alter_drop *drop;
     drop_it.rewind();
     while ((drop=drop_it++))
@@ -2315,7 +2306,7 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
       {						// Check if sub key
 	if (cfield->field->type() != FIELD_TYPE_BLOB &&
 	    (cfield->field->pack_length() == key_part_length ||
-	     cfield->length <= key_part_length / 
+	     cfield->length <= key_part_length /
 			       key_part->field->charset()->mbmaxlen))
 	  key_part_length=0;			// Use whole field
       }

sql/sql_yacc.yy

@@ -1689,7 +1689,6 @@ alter:
 	  if (!lex->select_lex.add_table_to_list(thd, $4, NULL,
 						 TL_OPTION_UPDATING))
 	    YYABORT;
-	  lex->drop_primary=0;
 	  lex->create_list.empty();
 	  lex->key_list.empty();
 	  lex->col_list.empty();
@@ -1761,12 +1760,14 @@ alter_list_item:
 	    lex->drop_list.push_back(new Alter_drop(Alter_drop::COLUMN,
 					    $3.str)); lex->simple_alter=0;
 	  }
+	| DROP FOREIGN KEY_SYM opt_ident { Lex->simple_alter=0; }
 	| DROP PRIMARY_SYM KEY_SYM
 	  {
 	    LEX *lex=Lex;
-	    lex->drop_primary=1; lex->simple_alter=0;
+	    lex->drop_list.push_back(new Alter_drop(Alter_drop::KEY,
+						    primary_key_name));
+	    lex->simple_alter=0;
 	  }
-	| DROP FOREIGN KEY_SYM opt_ident { Lex->simple_alter=0; }
 	| DROP key_or_index field_ident
 	  {
 	    LEX *lex=Lex;