BUG#21864838 SIG11 IN FIELD_BLOB::CMP| AT SQL/FIELD.CC

Bug#21881155: UNINTIALIZED READ IN KEY_REC_CMP CAUSE CRASH LATER

Problem :
---------
The issue is in generic partition handler that ensures order of
fetched records across partitions. It does a n-way merge with the
records from multiple partitions with the help of a priority queue.
The queue needs to compare records from different partitions based
on key (key_rec_cmp). key_rec_cmp() fails if the records contain
virtual columns.

Solution :
----------
All these comparisons are on the scan keys (virtual columns) from
the secondary index. For secondary index scan if we could always
return the evaluated secondary index key values in the record then
the issues would be resolved.

Reviewed-by: Jimmy Yang <[email protected]>

RB: 10686

Author: Debarun Banerjee

mysql-test/suite/innodb/r/partition.result

@@ -518,3 +518,30 @@ Warning	1013	InnoDB: Trying to get the free space for partition `test`.`t1` /* P
 Warning	1013	InnoDB: Trying to get the free space for partition `test`.`t1` /* Partition `p2` */ but its tablespace has been discarded or the .ibd file is missing. Setting the free space of the partition to zero.
 Warning	1013	InnoDB: Trying to get the free space for partition `test`.`t1` /* Partition `p3` */ but its tablespace has been discarded or the .ibd file is missing. Setting the free space of the partition to zero.
 DROP TABLE t1;
+#
+# Bug#21864838: SIG11 IN FIELD_BLOB::CMP| AT SQL/FIELD.CC
+#
+CREATE TABLE t1 (col1 INT PRIMARY KEY, col2 VARCHAR(1), col3 BLOB AS (REPEAT(col2, 500)) VIRTUAL, KEY(col3(100)))
+ENGINE=INNODB
+PARTITION BY HASH(col1) PARTITIONS 2;
+CREATE TABLE t2 (col1 INT PRIMARY KEY, col2 VARCHAR(1), col3 BLOB AS (REPEAT(col2, 500)) VIRTUAL, KEY(col3(100)))
+ENGINE=INNODB
+PARTITION BY HASH(col1) PARTITIONS 2;
+INSERT INTO t1 (col1, col2) VALUES(1, 'd'), (2, 'c'), (3, 'b'), (4, 'a');
+INSERT INTO t2 (col1, col2) VALUES(1, 'd'), (2, 'c'), (3, 'b'), (4, 'a');
+SELECT t1.col1 FROM t1, t2 where t1.col1 = 3 AND t1.col3 = t2.col3 ORDER BY t2.col1 DESC;
+col1
+3
+DROP TABLE t1;
+DROP TABLE t2;
+#
+# Bug #21881155: UNINTIALIZED READ IN KEY_REC_CMP CAUSE CRASH LATER
+#
+CREATE TABLE t1 (col1 int, col2 BLOB AS ('a') VIRTUAL, col3 INT,
+PRIMARY KEY(col1), KEY (col3, col2(1), col1))
+ENGINE=INNODB
+PARTITION BY KEY (col1) PARTITIONS 2;
+INSERT INTO t1(col1) values (1),(2);
+SELECT 1 FROM t1 WHERE col2 > 'a' GROUP BY col3;
+1
+DROP TABLE t1;

mysql-test/suite/innodb/t/partition.test

@@ -439,3 +439,37 @@ ALTER TABLE t1 DISCARD TABLESPACE;
 SELECT TABLE_ROWS FROM information_schema.tables where table_name = 't1';
 
 DROP TABLE t1;
+
+--echo #
+--echo # Bug#21864838: SIG11 IN FIELD_BLOB::CMP| AT SQL/FIELD.CC
+--echo #
+
+CREATE TABLE t1 (col1 INT PRIMARY KEY, col2 VARCHAR(1), col3 BLOB AS (REPEAT(col2, 500)) VIRTUAL, KEY(col3(100)))
+ENGINE=INNODB
+PARTITION BY HASH(col1) PARTITIONS 2;
+
+CREATE TABLE t2 (col1 INT PRIMARY KEY, col2 VARCHAR(1), col3 BLOB AS (REPEAT(col2, 500)) VIRTUAL, KEY(col3(100)))
+ENGINE=INNODB
+PARTITION BY HASH(col1) PARTITIONS 2;
+
+INSERT INTO t1 (col1, col2) VALUES(1, 'd'), (2, 'c'), (3, 'b'), (4, 'a');
+INSERT INTO t2 (col1, col2) VALUES(1, 'd'), (2, 'c'), (3, 'b'), (4, 'a');
+
+SELECT t1.col1 FROM t1, t2 where t1.col1 = 3 AND t1.col3 = t2.col3 ORDER BY t2.col1 DESC;
+
+DROP TABLE t1;
+DROP TABLE t2;
+
+--echo #
+--echo # Bug #21881155: UNINTIALIZED READ IN KEY_REC_CMP CAUSE CRASH LATER
+--echo #
+
+CREATE TABLE t1 (col1 int, col2 BLOB AS ('a') VIRTUAL, col3 INT,
+PRIMARY KEY(col1), KEY (col3, col2(1), col1))
+ENGINE=INNODB
+PARTITION BY KEY (col1) PARTITIONS 2;
+
+INSERT INTO t1(col1) values (1),(2);
+SELECT 1 FROM t1 WHERE col2 > 'a' GROUP BY col3;
+
+DROP TABLE t1;

storage/innobase/handler/ha_innopart.cc

@@ -1755,6 +1755,9 @@ ha_innopart::index_init(
 		m_prebuilt->m_no_prefetch = true;
 	}
 
+	/* For scan across partitions, the keys needs to be materialized */
+	m_prebuilt->m_read_virtual_key = true;
+
 	error = change_active_index(part_id, keynr);
 	if (error != 0) {
 		destroy_record_priority_queue();
@@ -1786,6 +1789,7 @@ ha_innopart::index_end()
 		destroy_record_priority_queue();
 		m_prebuilt->m_no_prefetch = false;
 	}
+	m_prebuilt->m_read_virtual_key = false;
 
 	DBUG_RETURN(ha_innobase::index_end());
 }

storage/innobase/include/row0mysql.h

@@ -896,6 +896,8 @@ struct row_prebuilt_t {
 	/** Disable prefetch. */
 	bool		m_no_prefetch;
 
+	/** Return materialized key for secondary index scan */
+	bool		m_read_virtual_key;
 };
 
 /** Callback for row_mysql_sys_index_iterate() */

storage/innobase/row/row0mysql.cc

@@ -989,6 +989,7 @@ row_create_prebuilt(
 	prebuilt->blob_heap = NULL;
 
 	prebuilt->m_no_prefetch = false;
+	prebuilt->m_read_virtual_key = false;
 
 	DBUG_RETURN(prebuilt);
 }

storage/innobase/row/row0sel.cc

@@ -3228,9 +3228,10 @@ row_sel_store_mysql_rec(
 		if (templ->is_virtual && dict_index_is_clust(index)) {
 
 			/* Skip virtual columns if it is not a covered
-			search */
+			search or virtual key read is not requested. */
 			if (!dict_index_has_virtual(prebuilt->index)
-			    || !prebuilt->read_just_key
+			    || (!prebuilt->read_just_key
+				&& !prebuilt->m_read_virtual_key)
 			    || !rec_clust) {
 				continue;
 			}
@@ -4517,10 +4518,12 @@ row_search_mvcc(
 		DBUG_RETURN(DB_CORRUPTION);
 	}
 
-	/* We need to get the virtual row value only if this is covered
-	index scan */
+	/* We need to get the virtual column values stored in secondary
+	index key, if this is covered index scan or virtual key read is
+	requested. */
 	bool    need_vrow = dict_index_has_virtual(prebuilt->index)
-			    && prebuilt->read_just_key;
+		&& (prebuilt->read_just_key
+		    || prebuilt->m_read_virtual_key);
 
 	/*-------------------------------------------------------------*/
 	/* PHASE 0: Release a possible s-latch we are holding on the