help with gzip

[saravan1]

Dear Sir/Mdm,

My name is Saravanan and I am a research assistant in National University
of Singapore. I am currently working on software change analysis and at
the moment, I am looking for a case study for my research. More
specifically, I need to find a senario where a change in the source code
has been made in version 1 to version 2 and a region affected by this
change is only rectified in version 2 to version 3. I have been trying to
find such a senario in gzip(Linux OS) rather unsuccessfully. I would
like to know if you have come across such cases or know where/how I can
find such a situation in gzip application. I will be grateful for any
information on my problem and your help will be very useful towards my
research.

Thank you.
Saravanan