#!/bin/sh
#
# This hook corrects any white spacing errors on what is about to be committed.
# Called by git-commit with no arguments.  The hook should exit with non-zero
# status after issuing an appropriate message, if it wants to stop the commit.
#
# If a whitespace error is found, it's corrected, it notifies the user that
# whitespace error was found, fixes the errors, removes the original, and
# adds it back to the staginging area.

# --- Config
allowwhitespace=$(git config --bool hooks.autowhitespace)
allowwhitespaceremoveoriginal=$(git config --bool hooks.whitespaceremoveoriginal)

if [ "$allowwhitespace" != "true" ]; then
  # Repository's config prevents us from performming this hook
  exit 0
fi

if git rev-parse --verify HEAD > /dev/null
then
  against=HEAD
else
  # Initial commit: diff against an empty tree object
  against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

old_IFS=$IFS
IFS=$'\n'

for FILE in `git diff-index --check --cached $against 2>&1 | sed '/^\+/d' | sed 's/:.*//' | uniq` ; do
  echo "WARNING: Trailing whitespaces are being removed for $FILE."
  sed -ie 's/[[:space:]]*$//' "$FILE"
  git add $FILE
  if [ "$allowwhitespaceremoveoriginal" = "true" ]; then
    rm $FILE"e"
  fi
done

IFS=$old_IFS

exit 0