I'm an electrical engineer working for a small startup. The company has its own software department (which I'm not part of). Writing software is not part of my job description. However, I do write my own unit-level tests. My codebase is separate from that of the software team one and is relatively primitive.
A coworker in software who is a veteran developer wrote a very useful utility which we both use for debugging any issues. Without talking to him about it, I forked it to my repository (with full version control).
I have made significant changes to this code over time. I changed and added some functionality but also changed the code to make it suit my coding style. The majority of the changes I made were purely to allow me to better understand the functionality and extend it.
I would like to share this code with my coworker who wrote the initial version so he can use it, however I'm not sure how I should go about it. I don't intend to merge my code with his, just tell him that my fork exists. I wonder if I should have asked first. He is a veteran in the industry (and about 20 years older than me) and I don't want to come across as disrespectful because I changed his code so significantly without asking.
Should I have asked first?