update.hook

#!/bin/sh

# INSTRUCTIONS:
#
# To install this file: copy it as <git repo>/.git/hooks/update into
# your repository. Before the revision of a branch is set to the new
# commit, every changed file since the actual revision of the branch
# will be checked by running the $CHECK_COMMAND and piping the files
# new content in that process. If the process was successful (exit
# code == 0), the file will be accepted. 

CHECK_COMMAND="false"

# --- Command line
refname="$1"
oldrev="$2"
newrev="$3"

# --- Safety check
if [ -z "$GIT_DIR" ]; then
	echo "Don't run this script from the command line." >&2
	echo " (if you want, you could supply GIT_DIR then run" >&2
	echo "  $0 <ref> <oldrev> <newrev>)" >&2
	exit 1
fi

if [ -z "$refname" -o -z "$oldrev" -o -z "$newrev" ]; then
	echo "usage: $0 <ref> <oldrev> <newrev>" >&2
	exit 1
fi

# --- Check types
zero="0000000000000000000000000000000000000000"
if [ "$newrev" = "$zero" ]; then
	newrev_type=delete
else
	newrev_type=$(git cat-file -t $newrev)
fi

#echo "refname: $refname"
#echo "oldrev: $oldrev"
#echo "newrev: $newrev"
#echo "newrev_type: $newrev_type"

files="$(git diff-tree --no-commit-id --name-only -r $newrev $refname | tr "\n" " ")"
echo "Affected files: $files"

case "$refname","$newrev_type" in
	refs/heads/*,commit)
		state=ok
		for f in $files; do

			if ! git cat-file --textconv $newrev:$f | $CHECK_COMMAND; then
				state=failed
				echo "File $f is corrupted."
			fi
		done;
		if [ "$state" == "failed" ]; then
			exit 1
		fi;
		echo "success! :)"
		;;
	*)
		;;
esac

exit 0