Re: [PATCH 2/7] stash: integrate with sparse index

> From: Victoria Dye <vdye@github.com>
>
> Enable sparse index in 'git stash' by disabling
> 'command_requires_full_index'.
>
> With sparse index enabled, some subcommands of 'stash' work without
> expanding the index, e.g., 'git stash', 'git stash list', 'git stash drop',
> etc. Others ensure the index is expanded either directly (as in the case of
> 'git stash [pop|apply]', where the call to 'merge_recursive_generic()' in
> 'do_apply_stash()' triggers the expansion), or in a command called
> internally by stash (e.g., 'git update-index' in 'git stash -u'). So, in
> addition to enabling sparse index, add tests to 't1092' demonstrating which
> variants of 'git stash' expand the index, and which do not.