v2git-gui: Handle Ctrl + BS/Del in the commit msg

> - Control+BackSpace: Delete word to the left of the cursor.
> - Control+Delete   : Delete word to the right of the cursor.
>
> Originally introduced by BRIEF and Turbo Vision between 1985 and 1992,
> they were adopted by most CUA-Compliant UIs, including those of: OS/2,
> Windows, Mac OS, Qt, GTK, Open/Libre Office, Gecko, and GNU Emacs.
>
> Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
> ---
>
> Notes:
>     Changes since v1:
>     - Improved commit message.

>  git-gui.sh | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/git-gui.sh b/git-gui.sh
> index 5bc21b878d41..e00d9a345294 100755
> --- a/git-gui.sh
> +++ b/git-gui.sh
> @@ -3788,6 +3788,8 @@ bind $ui_comm <$M1B-Key-KP_Subtract> {show_less_context;break}
>  bind $ui_comm <$M1B-Key-equal> {show_more_context;break}
>  bind $ui_comm <$M1B-Key-plus> {show_more_context;break}
>  bind $ui_comm <$M1B-Key-KP_Add> {show_more_context;break}
> +bind $ui_comm <Control-Key-BackSpace> {%W delete {insert -1 chars wordstart} insert;break}
> +bind $ui_comm <Control-Key-Delete> {%W delete insert {insert wordend};break}
>  
>  bind $ui_diff <$M1B-Key-x> {tk_textCopy %W;break}
>  bind $ui_diff <$M1B-Key-X> {tk_textCopy %W;break}

> Ismael Luceno <ismael@iodev.co.uk> writes:
> 
> > - Control+BackSpace: Delete word to the left of the cursor.
> > - Control+Delete   : Delete word to the right of the cursor.
> >
> > Originally introduced by BRIEF and Turbo Vision between 1985 and 1992,
> > they were adopted by most CUA-Compliant UIs, including those of: OS/2,
> > Windows, Mac OS, Qt, GTK, Open/Libre Office, Gecko, and GNU Emacs.
> >
> > Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
> > ---
> >
> > Notes:
> >     Changes since v1:
> >     - Improved commit message.
> 
> I do not use git-gui, but as a bystander, the intent of the change
> sounds sane.  deleting from the insertion cursor to the end of the
> word where the insertion cursor is looks like the right way to
> delete the word to the right of the cursor.  I am not sure if going
> back by one character from where the current insertion cursor is and
> further go back to the wordstart would give the beginning of the
> word to the left of the cursor, though.

>> ....  I am not sure if going
>> back by one character from where the current insertion cursor is and
>> further go back to the wordstart would give the beginning of the
>> word to the left of the cursor, though.
>
> ...
> Current implementation doesn't behave correctly when there's multiple
> spaces:

>> A larger issue is that we haven't heard from Pat, who has been
>> helping git-gui.sh maintenance, for quite a while, so we'd need to
>> find a volunteer to act as a replacement maintainer.  If you are
>> willing to, that would be great ;-)
>
> Sure.

> Ismael Luceno <ismael@iodev.co.uk> writes:
> 
> >> ....  I am not sure if going
> >> back by one character from where the current insertion cursor is and
> >> further go back to the wordstart would give the beginning of the
> >> word to the left of the cursor, though.
> >
> > ...
> > Current implementation doesn't behave correctly when there's multiple
> > spaces:
> 
> In short, I wondered if it is correct, and you say it is not correct.

> I would be surprised if git-gui were the only program that
> implemented an editor-like feature using tcl/tk, and none of the
> other editor implementations using tcl/tk had such an industry
> standard "delete previous word".  Perhaps you can see if there
> is already a correct implementation of the feature this patch can
> borrow from?