Post push fix for valgrind warning in ha_partition.cc

Bug#35161
Fixed memory leak when failing to open a partition.

Bug#20129
Added tests for verifying REPAIR PARTITION.

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

+CREATE TABLE t1_will_crash (a INT, KEY (a)) ENGINE=MyISAM;
+INSERT INTO t1_will_crash VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11);
+FLUSH TABLES;
+# replacing t1.MYI with a corrupt + unclosed one created by doing:
+# 'create table t1 (a int key(a))' head -c1024 t1.MYI > corrupt_t1.MYI 
+SELECT * FROM t1_will_crash;
+a
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+11
+Warnings:
+Error	145	Table './test/t1_will_crash' is marked as crashed and should be repaired
+Error	1194	Table 't1_will_crash' is marked as crashed and should be repaired
+Error	1034	1 client is using or hasn't closed the table properly
+Error	1034	Size of indexfile is: 1024        Should be: 2048
+Error	1034	Size of datafile is: 77       Should be: 7
+Error	1034	Number of rows changed from 1 to 11
+DROP TABLE t1_will_crash;
+CREATE TABLE t1_will_crash (a INT, KEY (a))
+ENGINE=MyISAM
+PARTITION BY HASH(a)
+PARTITIONS 3;
+INSERT INTO t1_will_crash VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11);
+FLUSH TABLES;
+# replacing t1#P#p1.MYI with a corrupt + unclosed one created by doing:
+# 'create table t1 (a int key(a)) partition by hash (a) partitions 3'
+# head -c1024 t1#P#p1.MYI > corrupt_t1#P#p1.MYI 
+SELECT * FROM t1_will_crash;
+a
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+11
+Warnings:
+Error	145	Table './test/t1_will_crash#P#p1' is marked as crashed and should be repaired
+Error	1194	Table 't1_will_crash' is marked as crashed and should be repaired
+Error	1034	1 client is using or hasn't closed the table properly
+Error	1034	Size of indexfile is: 1024        Should be: 2048
+Error	1034	Size of datafile is: 28       Should be: 7
+Error	1034	Number of rows changed from 1 to 4
+DROP TABLE t1_will_crash;

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

+# test the auto-recover (--myisam-recover) of partitioned myisam tables
+--source include/have_partition.inc
+--disable_warnings
+--disable_query_log
+drop table if exists t1_will_crash;
+--enable_query_log
+--enable_warnings
+
+
+CREATE TABLE t1_will_crash (a INT, KEY (a)) ENGINE=MyISAM;
+INSERT INTO t1_will_crash VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11);
+FLUSH TABLES;
+--echo # replacing t1.MYI with a corrupt + unclosed one created by doing:
+--echo # 'create table t1 (a int key(a))' head -c1024 t1.MYI > corrupt_t1.MYI 
+--remove_file $MYSQLTEST_VARDIR/master-data/test/t1_will_crash.MYI
+--copy_file std_data/corrupt_t1.MYI $MYSQLTEST_VARDIR/master-data/test/t1_will_crash.MYI
+SELECT * FROM t1_will_crash;
+DROP TABLE t1_will_crash;
+CREATE TABLE t1_will_crash (a INT, KEY (a))
+ENGINE=MyISAM
+PARTITION BY HASH(a)
+PARTITIONS 3;
+INSERT INTO t1_will_crash VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11);
+FLUSH TABLES;
+--echo # replacing t1#P#p1.MYI with a corrupt + unclosed one created by doing:
+--echo # 'create table t1 (a int key(a)) partition by hash (a) partitions 3'
+--echo # head -c1024 t1#P#p1.MYI > corrupt_t1#P#p1.MYI 
+--remove_file $MYSQLTEST_VARDIR/master-data/test/t1_will_crash#P#p1.MYI
+--copy_file std_data/corrupt_t1#P#p1.MYI $MYSQLTEST_VARDIR/master-data/test/t1_will_crash#P#p1.MYI
+SELECT * FROM t1_will_crash;
+DROP TABLE t1_will_crash;

sql/ha_partition.cc

@@ -2494,6 +2494,8 @@ int ha_partition::open(const char *name, int mode, uint test_if_locked)
 err_handler:
   while (file-- != m_file)
     (*file)->close();
+  if (!is_clone)
+    bitmap_free(&(m_part_info->used_partitions));
 
   DBUG_RETURN(error);
 }