Fix for bug #14863 "Triggers: crash if create and there is no current database".

Now when we create or drop trigger we check that both trigger name and trigger
table always have database part specified. Thus we give an error if it they
are not specified explicitly or implicitly via current database.

mysql-test/r/trigger.result

@@ -780,3 +780,9 @@ end//
 CALL p2();
 drop procedure p2;
 drop table t1;
+create trigger t1_bi before insert on test.t1 for each row set @a:=0;
+ERROR 3D000: No database selected
+create trigger test.t1_bi before insert on t1 for each row set @a:=0;
+ERROR 3D000: No database selected
+drop trigger t1_bi;
+ERROR 3D000: No database selected

mysql-test/t/trigger.test

@@ -13,6 +13,8 @@ drop procedure if exists p1;
 # Create additional connections used through test
 connect (addconroot1, localhost, root,,);
 connect (addconroot2, localhost, root,,);
+# Connection without current database set
+connect (addconwithoutdb, localhost, root,,*NO-ONE*);
 connection default;
 
 create table t1 (i int);
@@ -946,3 +948,16 @@ CALL p2();
 drop procedure p2;
 drop table t1;
 
+#
+# Test for bug #14863 "Triggers: crash if create and there is no current
+# database". We should not crash and give proper error when database for
+# trigger or its table is not specified and there is no current database.
+#
+connection addconwithoutdb;
+--error ER_NO_DB_ERROR
+create trigger t1_bi before insert on test.t1 for each row set @a:=0;
+--error ER_NO_DB_ERROR
+create trigger test.t1_bi before insert on t1 for each row set @a:=0;
+--error ER_NO_DB_ERROR
+drop trigger t1_bi;
+connection default;

sql/sql_trigger.cc

@@ -78,10 +78,6 @@ const char * const trigname_file_ext= ".TRN";
 static File_option trigname_file_parameters[]=
 {
   {
-    /*
-      FIXME: Length specified for "trigger_table" key is erroneous, problem
-      caused by this are reported as BUG#14090 and should be fixed ASAP.
-    */
     {STRING_WITH_LEN("trigger_table")},
     offsetof(struct st_trigname, trigger_table),
    FILE_OPTIONS_ESTRING
@@ -155,6 +151,17 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create)
     But do we want this ?
   */
 
+  /*
+    Note that once we will have check for TRIGGER privilege in place we won't
+    need second part of condition below, since check_access() function also
+    checks that db is specified.
+  */
+  if (!thd->lex->spname->m_db.length || create && !tables->db_length)
+  {
+    my_error(ER_NO_DB_ERROR, MYF(0));
+    DBUG_RETURN(TRUE);
+  }
+
   if (!create &&
       !(tables= add_table_for_trigger(thd, thd->lex->spname)))
     DBUG_RETURN(TRUE);
@@ -285,6 +292,9 @@ end:
                      definer. The caller is responsible to provide memory for
                      storing LEX_STRING object.
 
+  NOTE
+    Assumes that trigger name is fully qualified.
+
   RETURN VALUE
     False - success
     True  - error
@@ -307,9 +317,7 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables,
 
 
   /* Trigger must be in the same schema as target table. */
-  if (my_strcasecmp(table_alias_charset, table->s->db,
-                    lex->spname->m_db.str ? lex->spname->m_db.str :
-                                            thd->db))
+  if (my_strcasecmp(table_alias_charset, table->s->db, lex->spname->m_db.str))
   {
     my_error(ER_TRG_IN_WRONG_SCHEMA, MYF(0));
     return 1;
@@ -1010,7 +1018,6 @@ bool Table_triggers_list::get_trigger_info(THD *thd, trg_event_type event,
 
 static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig)
 {
-  const char *db= !trig->m_db.str ? thd->db : trig->m_db.str;
   LEX *lex= thd->lex;
   char path_buff[FN_REFLEN];
   LEX_STRING path;
@@ -1018,7 +1025,7 @@ static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig)
   struct st_trigname trigname;
   DBUG_ENTER("add_table_for_trigger");
 
-  strxnmov(path_buff, FN_REFLEN, mysql_data_home, "/", db, "/",
+  strxnmov(path_buff, FN_REFLEN, mysql_data_home, "/", trig->m_db.str, "/",
            trig->m_name.str, trigname_file_ext, NullS);
   path.length= unpack_filename(path_buff, path_buff);
   path.str= path_buff;
@@ -1047,7 +1054,7 @@ static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig)
   /* We need to reset statement table list to be PS/SP friendly. */
   lex->query_tables= 0;
   lex->query_tables_last= &lex->query_tables;
-  DBUG_RETURN(sp_add_to_query_tables(thd, lex, db,
+  DBUG_RETURN(sp_add_to_query_tables(thd, lex, trig->m_db.str,
                                      trigname.trigger_table.str, TL_WRITE));
 }