Re: [PATCH v2] add-patch: enforce only one-letter response to prompts

> In an "git add -p" session, especially when we are not using the
> single-char mode, we may see 'qa' as a response to a prompt
>
>   (1/2) Stage this hunk [y,n,q,a,d,j,J,g,/,e,p,?]?
>
> and then just do the 'q' thing (i.e. quit the session), ignoring
> everything other than the first byte.
>
> If 'q' and 'a' are next to each other on the user's keyboard, there
> is a plausible chance that we see 'qa' when the user who wanted to
> say 'a' fat-fingered and we ended up doing the 'q' thing instead.
>
> As we didn't think of a good reason during the review discussion why
> we want to accept excess letters only to ignore them, it appears to
> be a safe change to simply reject input that is longer than just one
> byte.
>
> The two exceptions are the 'g' command that takes a hunk number, and
> the '/' command that takes a regular expression.  They has to be

> accompanied by their operands (this makes me wonder how users who
> set the interactive.singlekey configuration feed these operands---it
> turns out that we notice there is no operand and give them another
> chance to type the operand separately, without using single key
> input this time), so we accept a string that is more than one byte
> long.
>
> Keep the "use only the first byte, downcased" behaviour when we ask
> yes/no question, though.  Neither on Qwerty or on Dvorak, 'y' and
> 'n' are not close to each other.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>