Fix bug #10624 Views with multiple UNION and UNION ALL produce incorrect

results.

st_select_lex_unit::print() was losing UNION ALL if in statement were present
UNION DISTINCT.


mysql-test/r/view.result:
  Test case for bug #10624  Views with multiple UNION and UNION ALL produce incorrect results.
mysql-test/t/view.test:
  Test case for bug #10624  Views with multiple UNION and UNION ALL produce incorrect results.
sql/sql_lex.cc:
  Fix bug #10624 Views with multiple UNION and UNION ALL produce incorrect results.

mysql-test/r/view.result

@@ -2097,3 +2097,15 @@ select * from v1;
 f1
 1
 drop view v1;
+create table t1 (f1 int);
+create table t2 (f1 int);
+insert into t1 values (1);
+insert into t2 values (2);
+create view v1 as select * from t1 union select * from t2 union all select * from t2;
+select * from v1;
+f1
+1
+2
+2
+drop view v1;
+drop table t1,t2;

mysql-test/t/view.test

@@ -1942,3 +1942,15 @@ DROP TABLE t1,t2,t3,t4,t5;
 create view v1 as select timestampdiff(day,'1997-01-01 00:00:00','1997-01-02 00:00:00') as f1;
 select * from v1;
 drop view v1;
+
+#
+# Bug #10624 Views with multiple UNION and UNION ALL produce incorrect results
+#
+create table t1 (f1 int);
+create table t2 (f1 int);
+insert into t1 values (1);
+insert into t2 values (2);
+create view v1 as select * from t1 union select * from t2 union all select * from t2;
+select * from v1;
+drop view v1;
+drop table t1,t2;

sql/sql_lex.cc

@@ -1511,13 +1511,16 @@ bool st_select_lex::setup_ref_array(THD *thd, uint order_group_num)
 
 void st_select_lex_unit::print(String *str)
 {
+  bool union_all= !union_distinct;
   for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())
   {
     if (sl != first_select())
     {
       str->append(" union ", 7);
-      if (!union_distinct)
+      if (union_all)
 	str->append("all ", 4);
+      else if (union_distinct == sl)
+        union_all= true;
     }
     if (sl->braces)
       str->append('(');