Re: [PATCHv2 8/9] checkout-index: Fix negations of even numbers of -n

[Eric Sunshine <sunshine@sunshineco.com>]

On Wed, Jul 31, 2013 at 12:28 PM, Stefan Beller
<stefanbeller@googlemail.com> wrote:
> The --no-create was parsed with OPT_BOOLEAN, which has a counting up
> logic implemented. Since b04ba2bb (parse-options: deprecate OPT_BOOLEAN,
> 2011-09-27) the OPT_BOOLEAN is deprecated and is only a define:
>         /* Deprecated synonym */
>         #define OPTION_BOOLEAN OPTION_COUNTUP
>
> However the variable not_new, which can be counted up by giving multiple
> --no-create multiple times, is used to set a bit in the struct checkout

s/multiple --no-create multiple times/--no-create multiple times/

> bitfield (defined in cache.h:969, declared at builtin/checkout-index.c:19):
>
>         state.not_new = not_new;
>
> When assigning a value other than 0 or 1 to a bit, all leading digits but
> the last are ignored and only the last bit is used for setting the bit
> variable.
>
> Hence the following:
>         # in git.git:
>         $ git status
>         # working directory clean
>         rm COPYING
>         $ git status
>         # deleted:    COPYING
>         $ git checkout-index -a -n
>         # deleted:    COPYING
>         # which is expected as we're telling git to not restore or create
>         # files, however:
>         $ git checkout-index -a -n -n
>         $ git status
>         # working directory clean, COPYING is restored again!
>         # That's the bug, we're fixing here.
>
> By restraining the variable not_new to a value being definitely 0 or 1
> by the macro OPT_BOOL the bug is fixed.
>
> Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>