Fixed bug #36055: mysql_upgrade doesn't really 'upgrade' tables

The REPAIR TABLE ... USE_FRM query silently corrupts data of tables
with old .FRM file version.
The mysql_upgrade client program or the REPAIR TABLE query (without
the USE_FRM clause) can't prevent this trouble, because in the
common case they don't upgrade .FRM file to compatible structure.

1. Evaluation of the REPAIR TABLE ... USE_FRM query has been
   modified to reject such tables with the message:
   "Failed repairing incompatible .FRM file".

2. REPAIR TABLE query (without USE_FRM clause) evaluation has been
   modified to upgrade .FRM files to current version.

3. CHECK TABLE ... FOR UPGRADE query evaluation has been modified
   to return error status when .FRM file has incompatible version.

4. mysql_upgrade and mysqlcheck client programs call CHECK TABLE
   FOR UPGRADE and REPAIR TABLE queries, so their behaviors have
   been changed too to upgrade .FRM files with incompatible
   version numbers.

mysql-test/r/repair.result

@@ -115,3 +115,39 @@ SET myisam_repair_threads=@@global.myisam_repair_threads;
 SET myisam_sort_buffer_size=@@global.myisam_sort_buffer_size;
 DROP TABLE t1;
 End of 4.1 tests
+# Test with a saved table from 4.1
+SHOW TABLE STATUS LIKE 't1';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	9	Fixed	2	5	10	21474836479	1024	0	NULL	#	#	NULL	latin1_swedish_ci	NULL		
+SELECT * FROM t1;
+id
+1
+2
+# Run CHECK TABLE, it should indicate table need a REPAIR TABLE
+CHECK TABLE t1 FOR UPGRADE;
+Table	Op	Msg_type	Msg_text
+test.t1	check	error	Table upgrade required. Please do "REPAIR TABLE `t1`" to fix it!
+# REPAIR old table USE_FRM should fail
+REPAIR TABLE t1 USE_FRM;
+Table	Op	Msg_type	Msg_text
+t1	repair	error	Failed reparing incompatible .FRM file
+# Run REPAIR TABLE to upgrade .frm file
+REPAIR TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	repair	status	OK
+SHOW TABLE STATUS LIKE 't1';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	10	Fixed	2	7	14	1970324836974591	1024	0	NULL	#	#	NULL	latin1_swedish_ci	NULL		
+SELECT * FROM t1;
+id
+1
+2
+REPAIR TABLE t1 USE_FRM;
+Table	Op	Msg_type	Msg_text
+test.t1	repair	warning	Number of rows changed from 0 to 2
+test.t1	repair	status	OK
+SELECT * FROM t1;
+id
+1
+2
+DROP TABLE t1;

mysql-test/t/repair.test

@@ -113,3 +113,33 @@ SET myisam_sort_buffer_size=@@global.myisam_sort_buffer_size;
 DROP TABLE t1;
 
 --echo End of 4.1 tests
+
+#
+# BUG#36055 - mysql_upgrade doesn't really 'upgrade' tables
+#
+
+--echo # Test with a saved table from 4.1
+--copy_file std_data/bug36055.frm $MYSQLTEST_VARDIR/master-data/test/t1.frm
+--copy_file std_data/bug36055.MYD $MYSQLTEST_VARDIR/master-data/test/t1.MYD
+--copy_file std_data/bug36055.MYI $MYSQLTEST_VARDIR/master-data/test/t1.MYI
+
+--replace_column 12 # 13 #
+SHOW TABLE STATUS LIKE 't1';
+SELECT * FROM t1;
+
+--echo # Run CHECK TABLE, it should indicate table need a REPAIR TABLE
+CHECK TABLE t1 FOR UPGRADE;
+
+--echo # REPAIR old table USE_FRM should fail
+REPAIR TABLE t1 USE_FRM;
+
+--echo # Run REPAIR TABLE to upgrade .frm file
+REPAIR TABLE t1;
+--replace_column 12 # 13 #
+SHOW TABLE STATUS LIKE 't1';
+SELECT * FROM t1;
+
+REPAIR TABLE t1 USE_FRM;
+SELECT * FROM t1;
+
+DROP TABLE t1;

sql/handler.cc

@@ -1980,6 +1980,8 @@ int handler::ha_check_for_upgrade(HA_CHECK_OPT *check_opt)
       }
     }
   }
+  if (table->s->frm_version != FRM_VER_TRUE_VARCHAR)
+    return HA_ADMIN_NEEDS_ALTER;
   return check_for_upgrade(check_opt);
 }
 

sql/sql_table.cc

@@ -2118,6 +2118,13 @@ static int prepare_for_repair(THD* thd, TABLE_LIST *table_list,
   const char **ext= table->file->bas_ext();
   MY_STAT stat_info;
 
+  if (table->s->frm_version != FRM_VER_TRUE_VARCHAR)
+  {
+    error= send_check_errmsg(thd, table_list, "repair",
+                             "Failed reparing incompatible .FRM file");
+    goto end;
+  }
+
   /*
     Check if this is a table type that stores index and data separately,
     like ISAM or MyISAM. We assume fixed order of engine file name