#!/bin/sh
#
# edit-patch 0.2
#
# http://termos.vemod.net/edit-patch
#
# Released into the public domain
#
# Please send bug reports and improvements to
# christoffer.sawicki@gmail.com

patch_original=`mktemp -t edit-patch`
patch_modified=`mktemp -t edit-patch`

echo "Reading patch..."

if [ -z "$EDITOR" ]; then
  EDITOR=vi
fi

cat > "$patch_original"

if [ -s "$patch_original" ]; then
  cp "$patch_original" "$patch_modified"

  $EDITOR "$patch_modified" < /dev/tty

  if [ "$(cat $patch_original)" != "$(cat $patch_modified)" ]; then
    patch -u -R < "$patch_original" | sed s/^patch/unpatch/
    
    patch -u < "$patch_modified"
    
    # TODO: Is this error handling sufficient?
    if [ $? -ne 0 ]; then
      echo "Whoops! Your modified patch was rejected."
      
      echo "Restoring..."
      patch -u < "$patch_original"
      
      echo "Saving patch as rejected.patch..."
      cp "$patch_modified" rejected.patch
    else
      echo "OK, done!"
    fi
  else
    echo "No changes were made to the patch."
  fi
else
  echo "No changes to edit."
fi

rm "$patch_original" "$patch_modified"