Git Auto Fixup script

git-auto-fixup.sh

#!/bin/bash
BASE_COMMIT=$1
if [[ -z $BASE_COMMIT ]]; then
	BASE_COMMIT=$(git rev-list --simplify-by-decoration --max-count 1 --skip 1 HEAD)
fi
git reset
MODIFIED_FILES=$(git status --porcelain | cut -c 4-)
for MODIFIED_FILE in $MODIFIED_FILES; do
	FILE_COMMITS=$(git --no-pager log --format='%H' $BASE_COMMIT..HEAD -- $MODIFIED_FILE)
	if [[ $(echo "$FILE_COMMITS" | wc -l) -gt 1 ]]; then
		echo "Skipping file $MODIFIED_FILE which is modified in more than one commit."
	elif [[ -z $FILE_COMMITS ]]; then
		echo "Skipping file $MODIFIED_FILE which is not modified in any commit."
	else
		FILES_TO_FIXUP=$(echo $FILES_TO_FIXUP; echo $MODIFIED_FILE)
	fi
done
COMMITS=$(git --no-pager log --format='%H' $BASE_COMMIT..HEAD)
for COMMIT in $COMMITS; do
	MODIFIED_FILES_IN_COMMIT=$(git show $COMMIT --name-only --pretty=format:)
	FILES_TO_FIXUP_IN_COMMIT=$(comm -12 <(echo "$FILES_TO_FIXUP" | sort) <(echo "$MODIFIED_FILES_IN_COMMIT" | sort))
	if [[ -n $FILES_TO_FIXUP_IN_COMMIT ]]; then
		git add $FILES_TO_FIXUP_IN_COMMIT
		git commit --fixup $COMMIT
	fi
done