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

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 4, 2023, 15:37 UTC
Message-ID: <xmqqo7o33bgt.fsf@gitster.g>
In-Reply-To: <3473764.PTxrJRyG3s@earendil>

Thorsten Otto <admin@tho-otto.de> writes:

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

The command is working as designed, either for newly added ones, modified ones, or deleted ones. In your sample output, we can see "Binary files differ", which is the default "diff" for binary contents. It is in line with the way "diff" by other people work.

Show 16 quoted lines

> What happened instead? (Actual behavior)
>
> The "git diff" command only showed a diff for the text file c, 
> but not for the binary file b:
>
> diff --git a/b b/b
> new file mode 100644
> index 0000000..a64a5a9
> Binary files /dev/null and b/b differ
> diff --git a/c b/c
> new file mode 100644
> index 0000000..ce01362
> --- /dev/null
> +++ b/c
> @@ -0,0 +1 @@
> +hello

As the primary purpose of "git format-patch" is to convey the content change between pair of states (i.e. change to bring the state at a particular commit to another state at a commit that is its child), it implicitly enables the "binary patch" option, but for "git diff" which is meant to be an interactive browser of changes for human consumption, the "binary patch" option is off by default.

You can run "git diff --binary".