From 1d3d64d69b9bf96a18768df031dc2cad29e84b15 Mon Sep 17 00:00:00 2001
From: unknown <ram@mysql.r18.ru>
Date: Mon, 8 Sep 2003 17:30:53 +0500
Subject: [PATCH] Fix for the bug #1209: SELECT DATABASE().

---
 mysql-test/r/create.result | 13 +++++++++++++
 mysql-test/t/create.test   | 16 ++++++++++++++++
 sql/item_strfunc.cc        |  4 ++--
 sql/sql_db.cc              |  2 ++
 4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/mysql-test/r/create.result b/mysql-test/r/create.result
index 80ff8aef15b..06ddd5e2280 100644
--- a/mysql-test/r/create.result
+++ b/mysql-test/r/create.result
@@ -361,3 +361,16 @@ a	b	c	d	e	f	g	h	dd
 1	-7	7	2000-01-01	b	2000-01-01 00:00:00	05:04:03	yet another binary data	02:00:00
 2	-2	2	1825-12-14	a	2003-01-01 03:02:01	04:03:02	binary data	02:00:00
 drop table t1, t2;
+drop database if exists test_$1;
+create database test_$1;
+use test_$1;
+select database();
+database()
+test_$1
+drop database test_$1;
+select database();
+database()
+NULL
+select database();
+database()
+NULL
diff --git a/mysql-test/t/create.test b/mysql-test/t/create.test
index 2e21768dc0b..0b86b67fdbf 100644
--- a/mysql-test/t/create.test
+++ b/mysql-test/t/create.test
@@ -260,3 +260,19 @@ select * from t2;
 
 drop table t1, t2;
 
+#
+# Bug #1209
+#
+
+--disable_warnings
+drop database if exists test_$1;
+--enable_warnings
+create database test_$1;
+use test_$1;
+select database();
+drop database test_$1;
+select database();
+
+# Connect without a database
+connect (user4,localhost,mysqltest_1,,*NO-ONE*);
+select database();
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index f8cc602129f..c4ad7f1e1e2 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -1454,8 +1454,8 @@ String *Item_func_database::val_str(String *str)
   THD *thd= current_thd;
   if (!thd->db)
   {
-    str->length(0);
-    str->set_charset(system_charset_info);
+    null_value= 1;
+    return 0;
   }
   else
     str->copy((const char*) thd->db,(uint) strlen(thd->db),system_charset_info);
diff --git a/sql/sql_db.cc b/sql/sql_db.cc
index 34e81402dd0..343eb6e42f2 100644
--- a/sql/sql_db.cc
+++ b/sql/sql_db.cc
@@ -391,6 +391,8 @@ int mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
 
 exit:
   start_waiting_global_read_lock(thd);
+  if (thd->db && !strcmp(thd->db, db))
+    thd->db= 0;
 exit2:
   VOID(pthread_mutex_unlock(&LOCK_mysql_create_db));