Support password stores from git worktree

[Kevin Lyda]

Git has supported git worktree for a while. Be nice if pass did.
Working directories created with git worktree have a .git file, not a
.git directory.

The easy way to apply it is to first fetch it:
git fetch https://github.com/lyda/password-store.git git-worktree

Then either make a branch to review and then merge it:
git checkout -b git-worktree FETCH_HEAD
git checkout master
git merge git-worktree

Or just merge it directly:
git merge FETCH_HEAD

If extracting from mail files is more fun, a patch follows:

>From 3dd1d7cb4669e5469e13c21667a781a93b7ca024 Mon Sep 17 00:00:00 2001
From: Kevin Lyda <kevin at ie.suberic.net>
Date: Mon, 28 Nov 2016 11:53:08 +0000
Subject: Allow for a git worktree repo.

Allow for a git worktree repo.

Say you have your password-store as a branch in a project. You can
then do this:

```bash
git clone git at gitserver:project.git
cd project
git branch password-store origin/password-store
git worktree add ../password-store password-store
```

Now both `project/` and `password-store/` use the same git repo.
However `password-store/.git` is a file, not a directory.

Arguably `test -e` is too permissive. A properly formatted `.git`
file in a worktree working dir will be
`^gitdir: /fqpn/project/.git/worktrees/password-store$` and we
could check for that. But it seems overkill to me.

As it stands pass won't really work with a worktree working dir
and this should fix that.
---
 src/password-store.sh | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/password-store.sh b/src/password-store.sh
index 63be840..e0dfc75 100755
--- a/src/password-store.sh
+++ b/src/password-store.sh
@@ -25,14 +25,14 @@ export GIT_WORK_TREE="${PASSWORD_STORE_GIT:-$PREFIX}"
 #

 git_add_file() {
- [[ -d $GIT_DIR ]] || return
+ [[ -e $GIT_DIR ]] || return
  git add "$1" || return
  [[ -n $(git status --porcelain "$1") ]] || return
  git_commit "$2"
 }
 git_commit() {
  local sign=""
- [[ -d $GIT_DIR ]] || return
+ [[ -e $GIT_DIR ]] || return
  [[ $(git config --bool --get pass.signcommits) == "true" ]] && sign="-S"
  git commit $sign -m "$1"
 }
@@ -277,7 +277,7 @@ cmd_init() {
  if [[ $# -eq 1 && -z $1 ]]; then
  [[ ! -f "$gpg_id" ]] && die "Error: $gpg_id does not exist and so
cannot be removed."
  rm -v -f "$gpg_id" || exit 1
- if [[ -d $GIT_DIR ]]; then
+ if [[ -e $GIT_DIR ]]; then
  git rm -qr "$gpg_id"
  git_commit "Deinitialize ${gpg_id}${id_path:+ ($id_path)}."
  fi
@@ -500,7 +500,7 @@ cmd_delete() {
  [[ $force -eq 1 ]] || yesno "Are you sure you would like to delete $path?"

  rm $recursive -f -v "$passfile"
- if [[ -d $GIT_DIR && ! -e $passfile ]]; then
+ if [[ -e $GIT_DIR && ! -e $passfile ]]; then
  git rm -qr "$passfile"
  git_commit "Remove $path from store."
  fi
@@ -541,7 +541,7 @@ cmd_copy_move() {
  mv $interactive -v "$old_path" "$new_path" || exit 1
  [[ -e "$new_path" ]] && reencrypt_path "$new_path"

- if [[ -d $GIT_DIR && ! -e $old_path ]]; then
+ if [[ -e $GIT_DIR && ! -e $old_path ]]; then
  git rm -qr "$old_path"
  git_add_file "$new_path" "Rename ${1} to ${2}."
  fi
@@ -562,7 +562,7 @@ cmd_git() {
  git_add_file .gitattributes "Configure git repository for gpg file diff."
  git config --local diff.gpg.binary true
  git config --local diff.gpg.textconv "$GPG -d ${GPG_OPTS[*]}"
- elif [[ -d $GIT_DIR ]]; then
+ elif [[ -e $GIT_DIR ]]; then
  tmpdir nowarn #Defines $SECURE_TMPDIR. We don't warn, because at
most, this only copies encrypted files.
  export TMPDIR="$SECURE_TMPDIR"
  git "$@"
-- 
2.10.2

Kevin

-- 
Kevin Lyda
Galway, Ireland