On Thu, Aug 03, 2023 at 01:16:02PM +0800, ZheNing Hu wrote: > > Here, it is necessary to compare multiple versions of blobs while also > > considering the situations of creation and deletion. > > > > Well, what I need is the "diff" content, with lines in the diff indicating > > '+' or '-' signs. This can be achieved by manually adding them, but it is > > not very compatible with the original logic. > > The native diff command itself supports comparison with an empty file. > > #diff -u /dev/null a > --- /dev/null 2023-07-25 16:47:50.270094301 +0800 > +++ a 2023-08-03 13:14:16.980262362 +0800 > @@ -0,0 +1 @@ > +a > > So I believe this feature would also be useful in git. Sure, you can easily diff any file against any other, including if either one or both are empty. I think the main difference here is that /dev/null exists on your system without additional configuration and the empty blob does not exist in a Git repository without additional configuration (in this case, `git hash-object -w -t blob --stdin </dev/null`). TBH, I don't know if /dev/null existing by default is necessarily a solid argument in favor of having Git repositories come initialized with the empty blob by default. (To be clear, when I say "initialized", I mean that a Git repository would recognize the empty blob object's hash for any value of `the_hash_algo`, not that every repository would be prepared with a loose object by default.) Thanks, Taylor
