Re: "git diff" does not show a diff for newly added, binary files

From: Jeff King <peff@peff.net>
Date: Apr 4, 2023, 15:36 UTC
Message-ID: <20230404153615.GA160693@coredump.intra.peff.net>
In-Reply-To: <2349908.kWcu0K8Tai@earendil>

On Tue, Apr 04, 2023 at 12:39:09PM +0200, Thorsten Otto wrote:

Show 22 quoted lines

> On Dienstag, 4. April 2023 12:17:43 CEST Kristoffer Haugsbakk wrote:
> 
> > Do you use `.gitattributes` to get these binary diffs? What does it look
> > like?
> 
> No, the repo was just created for demonstrating purposes. But when i commit 
> that last change, then do a "git --format-patch -1", i get something like
> 
> diff --git a/b b/b
> new file mode 100644
> index 
> 0000000000000000000000000000000000000000..a64a5a93fb4aef4d5f63d79cb2582731b9ac5063
> GIT binary patch
> literal 512
> NcmZQz7zHCa1ONg600961
> 
> literal 0
> HcmV?d00001
> 
> 
> I would expect "git diff" to output the same information. I don't see a reason 
> why it outputs the diff for a new text file, but not for a binary file?

The behavior you're seeing is expected.

The default for "git diff" is not to show binary patches, because they are often gigantic, and are meaningless to human readers. You can use "--binary" if you want to see them.

The default for "git format-patch" is different, because there the point is to send the patch to somebody to be applied with "git am", so it's important that all information is included.

-Peff