foo.perl

use XML::Simple;
use File::Slurp;

my $foo = read_file "foo.xml";
my $xml = eval { XMLin($foo); };
for my $patch_name (keys %{ $xml->{patch} }) {
  print "saw: $patch_name \n";
}

# $xml structure returned looks like this: 
#  'patch' => {
#    'resolved issue123: adding t.t' => {
#        'hash' => '20080215033723-20bb4-54f935f89817985a3e98f3de8e8ac9dad5e8e0e5.gz',
#        'inverted' => 'False',
#        'date' => '20080215033723',
#        'author' => 'Mark Stosberg <mark@summersault.com>',
#        'local_date' => 'Thu Feb 14 22:37:23 EST 2008'
#        },
#     'some other patch' => { ... }, 

foo.xml

<!-- what happens when you comment out one of the patches here? -->
<changelog>
<patch author='Ganesh Sittampalam &lt;ganesh@earth.li&gt;' date='20100314224948' local_date='Sun Mar 14 22:49:48 GMT 2010' inverted='False' hash='20100314224948-81bb2-fcda5a7f7a6aedb5e7783a772c286b9d0cd21574.gz'>
        <name>resolve issue1767: send CRC warnings to stderr</name>
        <comment>Ignore-this: b0555759c3fa55fc9689f9a957d9eb1</comment>
</patch>
<patch author='Reinier Lamers &lt;tux_rocker@reinier.de&gt;' date='20100221113357' local_date='Sun Feb 21 11:33:57 GMT 2010' inverted='False' hash='20100221113357-ead41-0d966e6b74660b574d2d6de4e6c4cc0c6cf9b0e0.gz'>
        <name>resolve issue1749: refuse to remove nonempty directories in makeRemovePatch</name>
        <comment>Ignore-this: ad57e75a8f336ca97a981e16933a74ea</comment>
</patch>
</changelog>