fixed union with prepared statement bug found by Konstantin

sql/sql_lex.cc:
  initialisation for safety
sql/sql_union.cc:
  item list should be saved in statement memory
tests/client_test.c:
  test suite

1 files changed, 57 insertions, 3 deletions

diff --git a/tests/client_test.c b/tests/client_test.c
index 31a53f6d81e..5aa48255a64 100644
--- a/tests/client_test.c
+++ b/tests/client_test.c
@@ -160,7 +160,10 @@ static void print_st_error(MYSQL_STMT *stmt, const char *msg)
 MYSQL_STMT *STDCALL
 mysql_simple_prepare(MYSQL  *mysql, const char *query)
 {
-  return mysql_prepare(mysql, query, strlen(query));
+  MYSQL_STMT *stmt= mysql_stmt_init(mysql);
+  if (mysql_stmt_prepare(stmt, query, strlen(query)))
+    return 0;
+  return stmt;
 }
 
 
@@ -8377,6 +8380,58 @@ static void test_subqueries_ref()
   myquery(rc);
 }
 
+
+static void test_union()
+{
+  MYSQL_STMT *stmt;
+  int rc;
+
+  myheader("test_union");
+ 
+  rc= mysql_query(mysql, "DROP TABLE IF EXISTS t1, t2");
+  myquery(rc);
+
+  rc= mysql_query(mysql,
+                  "CREATE TABLE t1 "
+                  "(id INTEGER NOT NULL PRIMARY KEY, "
+                  " name VARCHAR(20) NOT NULL)");
+  myquery(rc);
+  rc= mysql_query(mysql,
+                  "INSERT INTO t1 (id, name) VALUES "
+                  "(2, 'Ja'), (3, 'Ede'), "
+                  "(4, 'Haag'), (5, 'Kabul'), "
+                  "(6, 'Almere'), (7, 'Utrecht'), "
+                  "(8, 'Qandahar'), (9, 'Amsterdam'), "
+                  "(10, 'Amersfoort'), (11, 'Constantine')");
+  myquery(rc);
+  rc= mysql_query(mysql,
+                  "CREATE TABLE t2 "
+                  "(id INTEGER NOT NULL PRIMARY KEY, "
+                  " name VARCHAR(20) NOT NULL)");
+  myquery(rc);
+  rc= mysql_query(mysql,
+                  "INSERT INTO t2 (id, name) VALUES "
+                  "(4, 'Guam'), (5, 'Aruba'), "
+                  "(6, 'Angola'), (7, 'Albania'), "
+                  "(8, 'Anguilla'), (9, 'Argentina'), "
+                  "(10, 'Azerbaijan'), (11, 'Afghanistan'), "
+                  "(12, 'Burkina Faso'), (13, 'Faroe Islands')");
+  myquery(rc);
+ 
+  stmt= mysql_simple_prepare(mysql,
+                             "SELECT t1.name FROM t1 UNION "
+                             "SELECT t2.name FROM t2");
+  mystmt_init(stmt);
+
+  rc= mysql_stmt_execute(stmt);
+  mystmt(stmt,rc);
+  assert(20 == my_process_stmt_result(stmt));
+  mysql_stmt_close(stmt);
+
+  rc= mysql_query(mysql, "DROP TABLE t1, t2");
+  myquery(rc);
+}
+
 /*
   Read and parse arguments and MySQL options from my.cnf
 */
@@ -8634,8 +8689,7 @@ int main(int argc, char **argv)
     test_distinct();	    /* distinct aggregate functions */
     test_subqueries_ref();  /* outer reference in subqueries converted
 			       Item_field -> Item_ref */
-
-
+    test_union();	    /* test union with prepared statements */
 
     end_time= time((time_t *)0);
     total_time+= difftime(end_time, start_time);