Fix for bug #37310: 'on update CURRENT_TIMESTAMP' option crashes the table

Problem: data consistency check (maximum record length) for a correct
MyISAM table with CHECKSUM=1 and ROW_FORMAT=DYNAMIC option 
may fail due to wrong inner MyISAM parameter. In result we may 
have the table marked as 'corrupted'. 

Fix: properly set MyISAM maximum record length parameter.

myisam/mi_create.c

@@ -192,7 +192,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
   packed=(packed+7)/8;
   if (pack_reclength != INT_MAX32)
     pack_reclength+= reclength+packed +
-      test(test_all_bits(options, HA_OPTION_CHECKSUM | HA_PACK_RECORD));
+      test(test_all_bits(options, HA_OPTION_CHECKSUM | HA_OPTION_PACK_RECORD));
   min_pack_length+=packed;
 
   if (!ci->data_file_length && ci->max_rows)

mysql-test/r/myisam.result

@@ -1861,4 +1861,26 @@ id	ref
 3	2
 4	5
 DROP TABLE t1, t2;
+CREATE TABLE t1 (a INT) ENGINE=MyISAM CHECKSUM=1 ROW_FORMAT=DYNAMIC;
+INSERT INTO t1 VALUES (0);
+UPDATE t1 SET a=1;
+SELECT a FROM t1;
+a
+1
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+INSERT INTO t1 VALUES (0), (5), (4), (2);
+UPDATE t1 SET a=2;
+SELECT a FROM t1;
+a
+2
+2
+2
+2
+2
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+DROP TABLE t1;
 End of 5.0 tests

mysql-test/t/myisam.test

@@ -1210,4 +1210,19 @@ SELECT * FROM t1;
 
 DROP TABLE t1, t2;
 
+
+#
+# Bug#37310: 'on update CURRENT_TIMESTAMP' option crashes the table
+#
+CREATE TABLE t1 (a INT) ENGINE=MyISAM CHECKSUM=1 ROW_FORMAT=DYNAMIC;
+INSERT INTO t1 VALUES (0);
+UPDATE t1 SET a=1;
+SELECT a FROM t1;
+CHECK TABLE t1;
+INSERT INTO t1 VALUES (0), (5), (4), (2);
+UPDATE t1 SET a=2;
+SELECT a FROM t1;
+CHECK TABLE t1;
+DROP TABLE t1; 
+
 --echo End of 5.0 tests