bk commit into 5.0 tree (kostja:1.2228) BUG#21002

[konstantin]

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5.0 repository of kostja. When kostja does a push these changes will
be propagated to the main repository and, within 24 hours after the
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ChangeSet@stripped, 2006-07-19 14:11:40+04:00, kostja@stripped +7 -0
  A fix and a test case for Bug#21002 "Derived table not selecting from a 
  "real" table fails in JOINs".
  
  This is a regression caused by the fix for Bug 18444. 
  This fix removed the assignment of empty_c_string to table->db performed 
  in add_table_to_list, as neither me nor anyone else knew what it was 
  there for. Now we know it and it's covered with tests: the only case 
  when a table database name can be empty is when the table is a derived 
  table. The fix puts the assignment back but makes it a bit more explicit.
  
  Additionally, finally drop sp.result.orig which was checked in by mistake. 

  BitKeeper/deleted/.del-sp.result.orig@stripped, 2006-07-15 02:33:17+04:00, kostja@stripped
+0 -0
    Delete: mysql-test/r/sp.result.orig

  mysql-test/r/sp.result@stripped, 2006-07-19 14:11:37+04:00, kostja@stripped +15 -0
    Test results fixed (Bug#21002)

  mysql-test/t/sp.test@stripped, 2006-07-19 14:11:37+04:00, kostja@stripped +25 -0
    Add a test case for Bug#21002 "Derived table not selecting from a "real"
     table fails in JOINs"

  sql/sp.cc@stripped, 2006-07-19 14:11:37+04:00, kostja@stripped +0 -1
    Make empty_c_string globally accessible.

  sql/sql_class.cc@stripped, 2006-07-19 14:11:37+04:00, kostja@stripped +1 -0
    Add empty_c_string definition.

  sql/sql_class.h@stripped, 2006-07-19 14:11:37+04:00, kostja@stripped +12 -1
    Add a comment for the constructor of Table_ident which is
    used for derived tables. Make sure this constructor also initializes
    the database name, not only the table name.

  sql/sql_parse.cc@stripped, 2006-07-19 14:11:37+04:00, kostja@stripped +6 -2
    Don't call check_db_name for empty database. 
    Currently the only case when a table database name can be empty
    is when the table is a derived table.
    Report the right error if the database name is wrong (ER_WRONG_DB_NAME,
    not ER_WRONG_TABLE_NAME). 

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	kostja
# Host:	bodhi.local
# Root:	/opt/local/work/mysql-5.0-21002

--- 1.236/sql/sql_class.cc	2006-07-19 14:11:48 +04:00
+++ 1.237/sql/sql_class.cc	2006-07-19 14:11:48 +04:00
@@ -43,6 +43,7 @@
   table name
 */
 char internal_table_name[2]= "*";
+char empty_c_string[1]= {0};    /* used for not defined db */
 
 const char * const THD::DEFAULT_WHERE= "field list";
 

--- 1.292/sql/sql_class.h	2006-07-19 14:11:48 +04:00
+++ 1.293/sql/sql_class.h	2006-07-19 14:11:48 +04:00
@@ -41,6 +41,7 @@ enum enum_check_fields { CHECK_FIELD_IGN
 			 CHECK_FIELD_ERROR_FOR_NULL };
 
 extern char internal_table_name[2];
+extern char empty_c_string[1];
 extern const char **errmesg;
 
 #define TC_LOG_PAGE_SIZE   8192
@@ -1977,11 +1978,21 @@ public:
   {
     db.str=0;
   }
+  /*
+    This constructor is used only for the case when we create a derived
+    table. A derived table has no name and doesn't belong to any database.
+    Later, if there was an alias specified for the table, it will be set
+    by add_table_to_list.
+  */
   inline Table_ident(SELECT_LEX_UNIT *s) : sel(s)
   {
     /* We must have a table name here as this is used with add_table_to_list */
-    db.str=0; table.str= internal_table_name; table.length=1;
+    db.str= empty_c_string;                    /* a subject to casedn_str */
+    db.length= 0;
+    table.str= internal_table_name;
+    table.length=1;
   }
+  bool is_derived_table() const { return test(sel); }
   inline void change_db(char *db_name)
   {
     db.str= db_name; db.length= (uint) strlen(db_name);

--- 1.556/sql/sql_parse.cc	2006-07-19 14:11:49 +04:00
+++ 1.557/sql/sql_parse.cc	2006-07-19 14:11:49 +04:00
@@ -6088,8 +6088,7 @@ TABLE_LIST *st_select_lex::add_table_to_
   if (!table)
     DBUG_RETURN(0);				// End of memory
   alias_str= alias ? alias->str : table->table.str;
-  if (check_table_name(table->table.str,table->table.length) ||
-      table->db.str && check_db_name(table->db.str))
+  if (check_table_name(table->table.str, table->table.length))
   {
     my_error(ER_WRONG_TABLE_NAME, MYF(0), table->table.str);
     DBUG_RETURN(0);
@@ -6110,6 +6109,11 @@ TABLE_LIST *st_select_lex::add_table_to_
     DBUG_RETURN(0);				/* purecov: inspected */
   if (table->db.str)
   {
+    if (table->is_derived_table() == FALSE && check_db_name(table->db.str))
+    {
+      my_error(ER_WRONG_DB_NAME, MYF(0), table->db.str);
+      DBUG_RETURN(0);
+    }
     ptr->db= table->db.str;
     ptr->db_length= table->db.length;
   }

--- 1.202/mysql-test/r/sp.result	2006-07-19 14:11:49 +04:00
+++ 1.203/mysql-test/r/sp.result	2006-07-19 14:11:49 +04:00
@@ -5057,4 +5057,19 @@ concat('data was: /', var1, '/')
 data was: /1/
 drop table t3|
 drop procedure bug15217|
+drop table if exists t3|
+drop database if exists mysqltest1|
+create table t3 (a int)|
+insert into t3 (a) values (1), (2)|
+create database mysqltest1|
+use mysqltest1|
+drop database mysqltest1|
+select database()|
+database()
+NULL
+select * from (select 1 as a) as t1 natural join (select * from test.t3) as t2|
+a
+1
+use test|
+drop table t3|
 drop table t1,t2;

--- 1.190/mysql-test/t/sp.test	2006-07-19 14:11:49 +04:00
+++ 1.191/mysql-test/t/sp.test	2006-07-19 14:11:49 +04:00
@@ -5963,6 +5963,31 @@ drop table t3|
 drop procedure bug15217|
 
 #
+# Bug#21002 "Derived table not selecting from a "real" table fails in JOINs"
+#         
+# A regression caused by the fix for Bug#18444: for derived tables we should
+# set an empty string as the current database. They do not belong to any
+# database and must be usable even if there is no database
+# selected.
+--disable_warnings
+drop table if exists t3|
+drop database if exists mysqltest1|
+--enable_warnings
+create table t3 (a int)|
+insert into t3 (a) values (1), (2)|
+
+create database mysqltest1|
+use mysqltest1|
+drop database mysqltest1|
+
+# No current database
+select database()|
+
+select * from (select 1 as a) as t1 natural join (select * from test.t3) as t2|
+use test|
+drop table t3|
+
+#
 # BUG#NNNN: New bug synopsis
 #
 #--disable_warnings

--- 1.113/sql/sp.cc	2006-07-19 14:11:49 +04:00
+++ 1.114/sql/sp.cc	2006-07-19 14:11:49 +04:00
@@ -1846,7 +1846,6 @@ sp_use_new_db(THD *thd, LEX_STRING new_d
 	      bool no_access_check, bool *dbchangedp)
 {
   int ret;
-  static char empty_c_string[1]= {0};          /* used for not defined db */
   DBUG_ENTER("sp_use_new_db");
   DBUG_PRINT("enter", ("newdb: %s", new_db.str));