Comment 2 for bug 1136559

It seems to be just having too many databases causes the issue. The attached sql creates 100 databases and adds a table to the first one.

# cat /etc/redhat-release
CentOS release 5.9 (Final)

# perl -v
This is perl, v5.8.8 built for x86_64-linux-thread-multi

# rpm -qa perl*
perl-DBI-1.52-2.el5
perl-5.8.8-38.el5_8
perl-TermReadKey-2.30-4.el5
perl-String-CRC32-1.4-2.fc6
perl-DBD-MySQL-3.0007-2.el5

# mysql -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 26
Server version: 5.5.30-log Distributed by The IUS Community Project

# PTDEBUG=1 ./pt-table-checksum --tables foo0001.bla01 h=localhost,u=root --ask-pass
<snip>
# SchemaIterator:6888 3789 Next database: foo0097
# SchemaIterator:6894 3789 SHOW /*!50002 FULL*/ TABLES FROM `foo0097`
# SchemaIterator:6905 3789 Found 0 tables in database foo0097
# SchemaIterator:6933 3789 No more tables in database foo0097
# SchemaIterator:6872 3789 Getting next schema object from dbh DBI::db=HASH(0x134adcc0)
# SchemaIterator:6888 3789 Next database: foo0098
# SchemaIterator:6894 3789 SHOW /*!50002 FULL*/ TABLES FROM `foo0098`
# SchemaIterator:6905 3789 Found 0 tables in database foo0098
# SchemaIterator:6933 3789 No more tables in database foo0098
# SchemaIterator:6872 3789 Getting next schema object from dbh DBI::db=HASH(0x134adcc0)
# SchemaIterator:6888 3789 Next database: foo0099
# SchemaIterator:6894 3789 SHOW /*!50002 FULL*/ TABLES FROM `foo0099`
# SchemaIterator:6905 3789 Found 0 tables in database foo0099
# SchemaIterator:6933 3789 No more tables in database foo0099
Deep recursion on subroutine "SchemaIterator::_iterate_dbh" at ./pt-table-checksum line 6937.
# Cxn:3349 3789 Disconnecting dbh DBI::db=HASH(0x134adcc0) undef