/usr/lib/python3/dist-packages/git/test/fixtures/diff_file_with_spaces is in python3-git 2.1.1-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | diff --git a/file with spaces b/file with spaces
new file mode 100644
index 0000000000000000000000000000000000000000..75c620d7b0d3b0100415421a97f553c979d75174
--- /dev/null
+++ b/file with spaces
@@ -0,0 +1 @@
+ohai
|