Fix bug#13535 Incorrect result from SELECT statement after SHOW TABLE STATUS

After SHOW TABLE STATUS last_insert_id wasn't cleaned, and next select
erroneously rewrites WHERE condition and returs a row;
5.0 isn't affected because of different SHOW TABLE STATUS handling.

last_insert_id cleanup added to mysqld_extend_show_tables().

mysql-test/r/select.result

@@ -2626,3 +2626,13 @@ f1
 select f1 from t1,t2 where f1=f2 and (f1,f2) = ((1,NULL));
 f1
 drop table t1,t2;
+create table t1 (f1 int not null auto_increment primary key, f2 varchar(10));
+create table t11 like t1;
+insert into t1 values(1,""),(2,"");
+show table status like 't1%';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	9	Dynamic	2	20	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
+t11	MyISAM	9	Dynamic	0	0	X	X	X	X	X	X	X	X	latin1_swedish_ci	NULL		
+select 123 as a from t1 where f1 is null;
+a
+drop table t1,t11;

mysql-test/t/select.test

@@ -2174,4 +2174,14 @@ select f1 from t1,t2 where f1=f2 and (f1,NULL) = ((1,1));
 select f1 from t1,t2 where f1=f2 and (f1,f2) = ((1,NULL));
 drop table t1,t2; 
 
+#
+# Bug #13535
+#
+create table t1 (f1 int not null auto_increment primary key, f2 varchar(10));
+create table t11 like t1;
+insert into t1 values(1,""),(2,"");
+--replace_column 7 X 8 X 9 X 10 X 11 X 12 X 13 X 14 X
+show table status like 't1%';
+select 123 as a from t1 where f1 is null;
+drop table t1,t11;
 # End of 4.1 tests

sql/sql_show.cc

@@ -462,6 +462,7 @@ int mysqld_extend_show_tables(THD *thd,const char *db,const char *wild)
   TABLE *table;
   Protocol *protocol= thd->protocol;
   TIME time;
+  int res= 0;
   DBUG_ENTER("mysqld_extend_show_tables");
 
   (void) sprintf(path,"%s/%s",mysql_data_home,db);
@@ -632,10 +633,15 @@ int mysqld_extend_show_tables(THD *thd,const char *db,const char *wild)
       close_thread_tables(thd,0);
     }
     if (protocol->write())
-      DBUG_RETURN(-1);
+    {
+      res= -1;
+      break;
+    }
   }
-  send_eof(thd);
-  DBUG_RETURN(0);
+  thd->insert_id(0);
+  if (!res)
+    send_eof(thd);
+  DBUG_RETURN(res);
 }