Re: [PATCH 1/2] rebase: replace incorrect logical negation by correct bitwise one

[Junio C Hamano <gitster@pobox.com>]

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> In bff014dac7d9 (builtin rebase: support the `verbose` and `diffstat`
> options, 2018-09-04), we added a line that wanted to remove the
> `REBASE_DIFFSTAT` bit from the flags, but it used an incorrect negation.
>
> Found by Coverity.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  builtin/rebase.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index ba3a574e40..db6ca9bd7d 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -1203,7 +1203,7 @@ static int rebase_config(const char *var, const char *value, void *data)
>  		if (git_config_bool(var, value))
>  			opts->flags |= REBASE_DIFFSTAT;
>  		else
> -			opts->flags &= !REBASE_DIFFSTAT;
> +			opts->flags &= ~REBASE_DIFFSTAT;
>  		return 0;
>  	}

Obviously correct.  Thanks.

At this point in the codeflow, the .flags field is not touched by
parse_options() yet, the configuration codepath only touches that
field for REBASE_DIFFSTAT, and because REBASE_DIFFSTAT is not 0,
"[rebase] stat = no", which would want only the REBASE_DIFFSTAT bit
cleared in the word, can afford to instead assign 0 to the whole
word without causing any damage, which is funny way for this bug to
be hidden for a long time...