Failure to parse diff when it adds an empty file #6778

Reproduction steps

on any existing repo generate a diff that adds an empty file like this:

$ touch new_file
$ git add new_file 
$ git diff --staged > new_file.patch

(attaching here the produced path, I used git 2.25.1)
new_file.patch.txt

And when running this small program that uses libgit2:
test.c.txt
built using
gcc test.c -lgit2 -L <path to libgit2>/libgit2/build/ -Wall -pedantic -I <path to libgit2>/libgit2/include/
And run like this:
LD_LIBRARY_PATH=<path to libgit2>/libgit2/build/ ./a.out <Path to repo> <path to patch file>

Expected behavior

It successfully applies the change

Actual behavior

Error creating patch: unexpected header line 4

I checked while doing other changes and the only apparent issue seems to be including empty files

Version of libgit2 (release number or SHA1)

1.3.0 and main ( d74d491 )

Operating system(s) tested

Linux (Ubuntu 20.04)