Cross Projects in Git: Myth or Reality?

Question

git

Hello! There is a project X that lives its own life and develops. Git is used as a version control system, there is a large repository with a bunch of branches and commits. Now the task is to actually make a clone of the X project, with some changes (small, but in random parts of the project), let's call the project clone - Y. We did a "git clone" and placed the Y project in its own separate repository. Now, in fact, the question is how to organize a quick possibility of synchronous changes in the same parts of projects X and Y? Suppose a user has found a vulnerability caused by an error in the 30th line of the mainFail file, which is the same in both projects. How to make hotfix for two projects at the same time?

Answer 1

this is called a fork
when using all sorts of fancy things like github, it is done elementarily
to send fixes to the original project, pull requests are used

Answer 2

If the projects are almost identical, then they should not be separated, moreover, they should use the same code base.
And then all your problems and questions are resolved.