As part of my work at Zend (now a RogueWave company), I maintain the various patch sets. One of those is the changes for PDO_IBM extension for PHP.
After some patch exchange I decided it’s would be easier to manage the whole process over a public git repository, and maybe gain some more review / feedback along the way. Info at https://github.com/kaplanlior/pecl-database-pdo_ibm/commits/zend-patches
Another aspect of this, is having IBMi specific patches from YIPS (young i professionals) at http://www.youngiprofessionals.com/wiki/index.php/XMLService/PHP, which itself are patches on top of vanilla releases. Info at https://github.com/kaplanlior/pecl-database-pdo_ibm/commits/zend-patches-for-yips
So keeping track over these changes as well is easier while using git’s ability to rebase efficiently, so when a new release is done, I can adapt my patches quite easily. Make sure the changes can be back and forward ported between vanilla and IBMi versions of the extension.