Re: [PATCH v5 3/3] git-gui: revert untracked files by deleting them

> From: Jonathan Gilbert <JonathanG@iQmetrix.com>
> 
> Update the revert_helper proc to check for untracked files as well as
> changes, and then handle changes to be reverted and untracked files with
> independent blocks of code. Prompt the user independently for untracked
> files, since the underlying action is fundamentally different (rm -f).
> If after deleting untracked files, the directory containing them becomes
> empty, then remove the directory as well. Migrate unlocking of the index
> out of _close_updateindex to a responsibility of the caller, to permit
> paths that don't directly unlock the index, and refactor the error
> handling added in d4e890e5 so that callers can make flow control
> decisions in the event of errors. Update Tcl/Tk dependency from 8.4 to
> 8.6 in git-gui.sh.
> 
> A new proc delete_files takes care of actually deleting the files in
> batches, using the Tcler's Wiki recommended approach for keeping the UI
> responsive.
> 
> Since the checkout_index and delete_files calls are both asynchronous
> and could potentially complete in any order, a "chord" is used to
> coordinate unlocking the index and returning the UI to a usable state
> only after both operations are complete. The `SimpleChord` class,
> based on TclOO (Tcl/Tk 8.6), is added in this commit.
> 
> Signed-off-by: Jonathan Gilbert <JonathanG@iQmetrix.com>
> ---
>  git-gui.sh    |   4 +-
>  lib/chord.tcl | 160 +++++++++++++++++++
>  lib/index.tcl | 422 ++++++++++++++++++++++++++++++++++++++++----------
>  3 files changed, 502 insertions(+), 84 deletions(-)
>  create mode 100644 lib/chord.tcl