How to know core is modified?

Question

How to know if a magento core is modified or not? Would be handy if we could identify this before doing any maintainence on unknown sites.

Is there a way?

Answer 1

You can compare like this to see how much is actually modified. Take care to compare with the exact same patched version always for best results.

http://inchoo.net/magento/quickly-check-if-magento-core-files-are-modified/