Recursive Code on On Exception from pt-osc

[Jervin R]

1) Coredump when ALTER TABLE fails. The issue is that it will cause endless recursion. See patch file to fix the issue. The issue was introduced in 2.1
--- pt-online-schema-change.orig 2015-04-16 10:54:56.269371525 -0700
+++ pt-online-schema-change 2015-04-16 10:55:58.003839279 -0700
@@ -8575,9 +8575,9 @@
);

local $SIG{__DIE__} = sub {
+ undef $cleanup;
return if $EXCEPTIONS_BEING_CAUGHT;
local $EVAL_ERROR = $_[0];
- undef $cleanup;
die @_;
};

[Jervin R (revin)]

Credits to bug and path to customer on tagged issue.

[Frank Cizmich (frank-cizmich)]

This is a duplicate of https://bugs.launchpad.net/percona-toolkit/+bug/1446928
Although the title and summary description in this one are more accurate.
There's also a patch on the other report that works and uses a different approach.

[Frank Cizmich (frank-cizmich)]

Let's keep this one as the reference issue report because it's more accurate.

[Frank Cizmich (frank-cizmich)]

Including same patch as other report for convenience.