Merge gkodinov@bk-internal.mysql.com:/home/bk/mysql-5.0-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B29325-5.0-opt

include/my_base.h

@@ -284,6 +284,7 @@ enum ha_base_keytype {
 #define HA_PACK_RECORD		2	/* Request packed record format */
 #define HA_CREATE_TMP_TABLE	4
 #define HA_CREATE_CHECKSUM	8
+#define HA_CREATE_KEEP_FILES	16      /* don't overwrite .MYD and MYI */
 #define HA_CREATE_DELAY_KEY_WRITE 64
 
 /*

myisam/mi_create.c

@@ -586,7 +586,8 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
 					     32 : 0));
     linkname_ptr=0;
     /* Replace the current file */
-    create_flag=MY_DELETE_OLD;
+    if (!(flags & HA_CREATE_KEEP_FILES))
+      create_flag=MY_DELETE_OLD;
   }
 
   /*
@@ -647,7 +648,8 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
       {
 	fn_format(filename,name,"",MI_NAME_DEXT,4);
 	linkname_ptr=0;
-	create_flag=MY_DELETE_OLD;
+        if (!(flags & HA_CREATE_KEEP_FILES))
+          create_flag=MY_DELETE_OLD;
       }
       if ((dfile=
 	   my_create_with_symlink(linkname_ptr, filename, 0, create_mode,

mysql-test/r/create.result

@@ -1503,4 +1503,21 @@ t1	CREATE TABLE `t1` (
   `c17` int(11) default NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+CREATE DATABASE db1;
+CREATE DATABASE db2;
+USE db2;
+INSERT INTO db2.t1 VALUES (1);
+SELECT * FROM db2.t1;
+b
+1
+RESET QUERY CACHE;
+USE db1;
+SET SESSION keep_files_on_create = TRUE;
+CREATE TABLE t1 (a INT) ENGINE MYISAM;
+ERROR HY000: Can't create/write to file './db1/t1.MYD' (Errcode: 17)
+SET SESSION keep_files_on_create = DEFAULT;
+DROP TABLE db2.t1;
+DROP DATABASE db1;
+DROP DATABASE db2;
+USE test;
 End of 5.0 tests

mysql-test/t/create.test

@@ -1118,5 +1118,36 @@ show create table t1;
 
 drop table t1;
 
+#
+# Bug #29325: create table overwrites .MYD file of other table (datadir)
+#
+
+CREATE DATABASE db1; 
+CREATE DATABASE db2;
+
+USE db2;
+--disable_query_log
+eval CREATE TABLE t1 (b INT) ENGINE MYISAM
+DATA DIRECTORY = '$MYSQLTEST_VARDIR/master-data/db1/';
+--enable_query_log
+
+INSERT INTO db2.t1 VALUES (1);
+SELECT * FROM db2.t1;
+RESET QUERY CACHE;
+
+USE db1;
+
+#no warning from create table
+SET SESSION keep_files_on_create = TRUE;
+--disable_abort_on_error
+CREATE TABLE t1 (a INT) ENGINE MYISAM;
+--enable_abort_on_error
+SET SESSION keep_files_on_create = DEFAULT;
+
+DROP TABLE db2.t1;
+DROP DATABASE db1;
+DROP DATABASE db2;
+USE test;
+
 
 --echo End of 5.0 tests

sql/ha_myisam.cc

@@ -1809,6 +1809,8 @@ int ha_myisam::create(const char *name, register TABLE *table_arg,
 
   if (ha_create_info->options & HA_LEX_CREATE_TMP_TABLE)
     create_flags|= HA_CREATE_TMP_TABLE;
+  if (ha_create_info->options & HA_CREATE_KEEP_FILES)
+    create_flags|= HA_CREATE_KEEP_FILES;
   if (options & HA_OPTION_PACK_RECORD)
     create_flags|= HA_PACK_RECORD;
   if (options & HA_OPTION_CHECKSUM)

sql/set_var.cc

@@ -592,6 +592,10 @@ sys_var_const_str		sys_license("license", STRINGIFY_ARG(LICENSE));
 /* Global read-only variable containing hostname */
 sys_var_const_str		sys_hostname("hostname", glob_hostname);
 
+sys_var_thd_bool  sys_keep_files_on_create("keep_files_on_create", 
+                                           &SV::keep_files_on_create);
+							    
+
 
 
 /*
@@ -637,6 +641,7 @@ sys_var *sys_variables[]=
   &sys_delayed_insert_limit,
   &sys_delayed_insert_timeout,
   &sys_delayed_queue_size,
+  &sys_keep_files_on_create,
   &sys_error_count,
   &sys_expire_logs_days,
   &sys_flush,
@@ -849,6 +854,7 @@ struct show_var_st init_vars[]= {
   {sys_delayed_insert_timeout.name, (char*) &sys_delayed_insert_timeout, SHOW_SYS},
   {sys_delayed_queue_size.name,(char*) &sys_delayed_queue_size,     SHOW_SYS},
   {sys_div_precincrement.name,(char*) &sys_div_precincrement,SHOW_SYS},
+  {sys_keep_files_on_create.name,(char*) &sys_keep_files_on_create, SHOW_SYS},
   {sys_engine_condition_pushdown.name,
    (char*) &sys_engine_condition_pushdown,                          SHOW_SYS},
   {sys_expire_logs_days.name, (char*) &sys_expire_logs_days,        SHOW_SYS},

sql/sql_class.h

@@ -566,6 +566,7 @@ struct system_variables
   my_bool new_mode;
   my_bool query_cache_wlock_invalidate;
   my_bool engine_condition_pushdown;
+  my_bool keep_files_on_create;
 
 #ifdef HAVE_INNOBASE_DB
   my_bool innodb_table_locks;

sql/sql_table.cc

@@ -2841,6 +2841,8 @@ bool mysql_create_like_table(THD* thd, TABLE_LIST* table, TABLE_LIST *src_table,
     and temporary tables).
   */
   *fn_ext(dst_path)= 0;
+  if (thd->variables.keep_files_on_create)
+    create_info->options|= HA_CREATE_KEEP_FILES;
   err= ha_create_table(dst_path, create_info, 1);
 
   if (create_info->options & HA_LEX_CREATE_TMP_TABLE)

sql/unireg.cc

@@ -285,6 +285,8 @@ int rea_create_table(THD *thd, my_string file_name,
   if (mysql_create_frm(thd, file_name, db, table, create_info,
                        create_fields, keys, key_info, NULL))
     DBUG_RETURN(1);
+  if (thd->variables.keep_files_on_create)
+    create_info->options|= HA_CREATE_KEEP_FILES;
   if (!create_info->frm_only && ha_create_table(file_name,create_info,0))
   {
     my_delete(file_name,MYF(0));