git-diffn.sh generates line numbers for /dev/null (when file is added or removed)

[camac]

Note: Thank you for sharing the helpful git-diffn.sh script. I will follow up with a PR that fixes this issue. I am just recording the issue so it is searchable for anyone else using the script.

The git diff uses /dev/null as the source path when a file is added, and when a file is removed /dev/null is used as a destination path.
For example when a file is removed:

--- a/some/file.txt
+++ /dev/null

The git-diffn.sh script does not take this into account (it only expects a/somefile.txt or b/somefile.txt. This means /dev/null is prepended with a line number that doesn't make sense (leftover from the above linenumbers).

e.g.

--- a/some/file.txt
+      162:+++ /dev/null