Fix bug #9728 decreased functionality in "on duplicate key update"

Remove changes made by bug fix #8147. They strips list of insert_table_list to
only insert table, which results in error reported in bug #9728.
Added flag to Item to resolve ambigous fields reported in bug #8147.


sql/item.h:
  Fix bug#9728  decreased functionality in "on duplicate key update".
sql/item.cc:
  Fix bug#9728  decreased functionality in "on duplicate key update"
sql/sql_parse.cc:
  Fix bug#9728  decreased functionality in "on duplicate key update"
sql/sql_base.cc:
  Fix bug#9728  decreased functionality in "on duplicate key update".
sql/sql_yacc.yy:
  Fix bug#9728  decreased functionality in "on duplicate key update"
mysql-test/t/insert_select.test:
  Test case for bug#9728 Decreased functionality in "on duplicate key update".
mysql-test/r/insert_select.result:
  Test case for bug#9728 Decreased functionality in "on duplicate key update".

1 files changed, 14 insertions, 0 deletions

diff --git a/mysql-test/t/insert_select.test b/mysql-test/t/insert_select.test
index 613c97dc4f1..7402940fa52 100644
--- a/mysql-test/t/insert_select.test
+++ b/mysql-test/t/insert_select.test
@@ -175,3 +175,17 @@ insert into t1 values (1),(1),(2);
 insert into t2(ff1) select f1 from t1 on duplicate key update ff2=ff2+1;
 select * from t2;
 drop table t1, t2;
+#
+# BUGS #9728 - 'Decreased functionality in "on duplicate key update"' 
+#      #8147 - 'a column proclaimed ambigous in INSERT ... SELECT .. ON
+#      DUPLICATE'
+#
+create table t1 (a int unique);
+create table t2 (a int, b int);
+insert into t1 values (1),(2);
+insert into t2 values (1,2);
+select * from t1;
+insert into t1 select t2.a from t2 on duplicate key update a= a + t2.b;
+select * from t1;
+drop table t1;
+drop table t2;