tips/automatically_adding_metadata/pre-commit-annex: Fix to not silently
skip filenames containing non-ascii characters.
git diff-index defaults to munging non-ascii characters. Using -z makes
it not do that, and then we just change the nulls to newlines.
This commit was sponsored by Jochen Bartl on Patreon.
Using the extract(1) program to do the heavy lifting.
Decided to make git-annex run pre-commit-annex when committing. Since
git-annex pre-commit also runs it, it'll be run when git commit is run too,
via the pre-commit hook. This basically gives back the pre-commit hook
that git-annex took away. The implementation avoids repeatedly looking
for the hook script when the assistant is running and committing
repeatedly; only checks if the hook is available once.
To make the script simpler, made git-annex metadata -s field?=value
only set a field when it's not already got a value.
This commit was sponsored by bak.