- parent_sha1=$(git rev-parse --verify "$1"^ 2> /dev/null)
- git diff "$parent_sha1".."$1" > "$DOTEST"/patch
+ parent_sha1=$(git rev-parse --verify "$1"^) ||
+ die "Cannot get patch for $1^"
+ git diff-tree -p "$parent_sha1".."$1" > "$DOTEST"/patch
+ test -f "$DOTEST"/message ||
+ git cat-file commit "$1" | sed "1,/^$/d" > "$DOTEST"/message
+ test -f "$DOTEST"/author-script ||
+ get_author_ident_from_commit "$1" > "$DOTEST"/author-script