Merge pull request #13 from percona-ysorokin/ps-8.0-bug1657941-part_t…

…able_crash

Fix bug 76418 / 1657941 (Server crashes when querying partitioning table MySQL_5.7.14)

mysql-test/suite/parts/r/bug76418.result

@@ -0,0 +1,13 @@
+CREATE TABLE t1(
+id INT UNSIGNED NOT NULL,
+dttm DATETIME NOT NULL,
+PRIMARY KEY(id, dttm)
+) ENGINE=InnoDB
+PARTITION BY RANGE COLUMNS(dttm) (
+PARTITION pf_201612 VALUES LESS THAN ('20170101') ENGINE=InnoDB
+);
+SELECT * FROM t1 WHERE dttm > '2017-01-19' ORDER BY id DESC;
+id	dttm
+SELECT * FROM t1 WHERE dttm > '2017-01-19' ORDER BY id ASC;
+id	dttm
+DROP TABLE t1;

mysql-test/suite/parts/t/bug76418.test

@@ -0,0 +1,17 @@
+#
+# lp:1657941 / Oracle Bug #76418 "Server crashes when querying partitioning table"
+#
+
+CREATE TABLE t1(
+  id INT UNSIGNED NOT NULL,
+  dttm DATETIME NOT NULL,
+  PRIMARY KEY(id, dttm)
+) ENGINE=InnoDB
+PARTITION BY RANGE COLUMNS(dttm) (
+  PARTITION pf_201612 VALUES LESS THAN ('20170101') ENGINE=InnoDB
+);
+
+SELECT * FROM t1 WHERE dttm > '2017-01-19' ORDER BY id DESC;
+SELECT * FROM t1 WHERE dttm > '2017-01-19' ORDER BY id ASC;
+
+DROP TABLE t1;

sql/partitioning/partition_handler.cc

@@ -2694,12 +2694,20 @@ int Partition_helper::partition_scan_set_up(uchar * buf, bool idx_read_flag)
                       &m_part_spec);
   else
   {
-    // TODO: set to get_first_used_part() instead!
-    m_part_spec.start_part= 0;
-    // TODO: Implement bitmap_get_last_set() and use that here!
-    m_part_spec.end_part= m_tot_parts - 1;
+    m_part_spec.start_part= m_part_info->get_first_used_partition();
+    m_part_spec.end_part= m_part_spec.start_part;
+
+    uint i= m_part_spec.end_part;
+    while (i != MY_BIT_NONE)
+    {
+      i= m_part_info->get_next_used_partition(i);
+      if (i != MY_BIT_NONE)
+        m_part_spec.end_part= i;
+    }
   }
-  if (m_part_spec.start_part > m_part_spec.end_part)
+  if (m_part_spec.start_part == MY_BIT_NONE ||
+      m_part_spec.end_part == MY_BIT_NONE ||
+      m_part_spec.start_part > m_part_spec.end_part)
   {
     /*
       We discovered a partition set but the set was empty so we report