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

[Thorsten Otto <admin@tho-otto.de>]

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

What did you do before the bug happened? (Steps to reproduce your issue)

$ git init .
$ touch a
$ git add a
$ git commit -m "first commit"
$ dd if=/dev/zero of=b count=1
$ git add b
$ echo hello > c
$ git add c
$ git diff --cached

What did you expect to happen? (Expected behavior)

I expected a binary diff for the new file, just like it is done
when comparing two different, already committed revisions.

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

[System Info]
git version:
git version 2.39.0
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
uname: Linux 6.1.3-1-default #1 SMP PREEMPT_DYNAMIC Wed Jan  4 11:03:53 UTC 
2023 (a5315fb) x86_64
compiler info: gnuc: 12.2
libc info: glibc: 2.36
$SHELL (typically, interactive shell): /bin/bash


[Enabled Hooks]