Hi, Alan, On Aug 16, 2014, at 11:03 AM, Alan W. Irwin wrote:
> Ideas from the git gurus, please. I think the ongoing concern/discussion of deleting branches in git might be due to a lingering svn mindset vis a vis branching. I could be wrong, but I think deleting a branch in subversion also deletes the entire set of commits that lived on that branch. This is not the case at all in git. In git, "commits" are first class objects in their own right, whereas "branches" are just pointers (aka references) to commits. If someone deletes a branch locally, the commit pointed to by the branch (before it was deleted) still exists in the git repository (as do all of its ancestral commits as well). Pushing the deletion of a branch so that the branch is also deleted in the remote repository is possible but not something that can be done by mistake; you really have to actively/explicitly delete the remote branch, but again the commits themselves are not deleted. The reflog tracks the local history of where references point in the local repository. This information is inherently local. Why would anyone but me care where my HEAD reference pointed at various points in my workflow? More importantly, if reflog info were not local, how would the histories of "HEAD" for multiple developers be reconciled? What would it mean to anyone anyway? When I was starting with git (from a CVS/SVN background), the thing that really helped me to understand git was reading about the four types of objects that git stores (blobs, trees, commits, and tags). Section 9.2 of the Pro Git book covers this material (though I think I first read about it elsewhere): http://git-scm.com/book/en/Git-Internals-Git-Objects It's also important to note that tags in git come in two types: lightweight tags and heavyweight tags. Both kinds of tags "point" to a specific commit, but lightweight tags are just references (like branches) whereas heavyweight tags are first class objects (like commits). For tagging releases, I far prefer heavyweight tags because they include extra metadata that a lightweight tag cannot (e.g. who created the tag, when it was created, optional message about the tag, optional signing of the tag). Hope this helps, Dave P.S. Another thing I really like about git is "gitk" which can be used to visualize and explore a git repo's history. Try that with subversion! :-) ------------------------------------------------------------------------------ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
