Re: [PATCH v2] pull: pass --signoff/--no-signoff to "git merge"

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

"W. Trevor King" <wking@tremily.us> writes:

> e379fdf3 (merge: refuse to create too cool a merge by default,
> 2016-03-18) gave a reason for *not* passing options from pull to
> merge:
>
>   ...because such a "two project merge" would be done after fetching
>   the other project into some location in the working tree of an
>   existing project and making sure how well they fit together...

Read the above again and notice the phrase "two project merge".  The
reasoning applies only to the --allow-unrelated-histories option.
It gave a reason for not passing *THAT* option and nothing else, and
does not mean to say anything about passing or not passing any other
options.  

That is why I said the reference to that commit was irrelevant in
the context of this patch.

If you find somebody saying "we should not pass --signoff from pull
to merge" when we taught "--signoff" to "merge", then that may be
worth referring to, as this commit _will_ be changing that earlier
decision.  I however do not think that is a case.  Just saying
"merge can take --signoff, but without pull passing --signoff down,
it is inconvenient, so let's pass it through" is sufficient to
justify this change.

> diff --git a/t/t5521-pull-options.sh b/t/t5521-pull-options.sh
> index ded8f98dbe..82680a30f8 100755
> --- a/t/t5521-pull-options.sh
> +++ b/t/t5521-pull-options.sh
> @@ -165,4 +165,44 @@ test_expect_success 'git pull --allow-unrelated-histories' '
>  	)
>  '
>  
> +test_expect_success 'git pull does not add a sign-off line' '
> +	test_when_finished "rm -fr src dst" &&
> +	git init src &&
> +	test_commit -C src one &&
> +	git clone src dst &&
> +	test_commit -C src two &&
> +	git -C dst pull --no-ff &&
> +	! test_has_trailer -C dst HEAD Signed-off-by
> +'
> +
> +test_expect_success 'git pull --no-signoff does not add sign-off line' '
> +	test_when_finished "rm -fr src dst" &&
> +	git init src &&
> +	test_commit -C src one &&
> +	git clone src dst &&
> +	test_commit -C src two &&
> +	git -C dst pull --no-signoff --no-ff &&
> +	! test_has_trailer -C dst HEAD Signed-off-by
> +'
> +
> +test_expect_success 'git pull --signoff add a sign-off line' '
> +	test_when_finished "rm -fr src dst" &&
> +	git init src &&
> +	test_commit -C src one &&
> +	git clone src dst &&
> +	test_commit -C src two &&
> +	git -C dst pull --signoff --no-ff &&
> +	test_has_trailer -C dst HEAD Signed-off-by "$GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
> +'
> +
> +test_expect_success 'git pull --no-signoff flag cancels --signoff flag' '
> +	test_when_finished "rm -fr src dst actual" &&
> +	git init src &&
> +	test_commit -C src one &&
> +	git clone src dst &&
> +	test_commit -C src two &&
> +	git -C dst pull --signoff --no-signoff --no-ff &&
> +	! test_has_trailer -C dst HEAD Signed-off-by
> +'
> +
>  test_done
> diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
> index 1701fe2a06..08409b1c25 100644
> --- a/t/test-lib-functions.sh
> +++ b/t/test-lib-functions.sh
> @@ -726,6 +726,49 @@ test_must_be_empty () {
>  	fi
>  }
>  
> +# Call test_has_trailer with the arguments:
> +# [-C <directory>] <object> <token> [<value>]
> +# where <object> is an object name as described in gitrevisions(7),
> +# <token> is a trailer token (e.g. 'Signed-off-by'), and
> +# <value> is an optional value (e.g. 'A U Thor <author@example.com>').
> +# test_has_trailer returns success if the specified trailer is found
> +# in the object content.  If <value> is unset, any value will match.
> +#
> +# Both <token> and <value> are basic regular expressions.
> +#
> +# If the first argument is "-C", the second argument is used as a path for
> +# the git invocations.
> +test_has_trailer () {
> +	INDIR=
> +	case "$1" in
> +	-C)
> +		INDIR="$2"
> +		shift 2 || error "<directory> not specified"
> +		;;
> +	esac
> +	INDIR="${INDIR:+${INDIR}/}"
> +	OBJECT="$1"
> +	shift || error "<object> not specified"
> +	TOKEN="$1"
> +	shift || error "<token> not specified"
> +	SEP=':'  # FIXME: read from trailer.separators?
> +	CONTENT="$(git ${INDIR:+ -C "${INDIR}"} cat-file -p "${OBJECT}")" || error "object ${OBJECT} not found${INDIR:+ in ${INDIR}}"
> +	PATTERN="^${TOKEN}${SEP}"
> +	if test 0 -lt "$#"
> +	then
> +		VALUE="$1"
> +		PATTERN="${PATTERN} *${VALUE}$"
> +	fi
> +	if (echo "${CONTENT}" | grep -q "${PATTERN}")
> +	then
> +		printf "%s found in:\n%s\n" "${PATTERN}" "${CONTENT}"
> +		return 0
> +	else
> +		printf "%s not found in:\n%s\n" "${PATTERN}" "${CONTENT}"
> +		return 1
> +	fi
> +}

The reason why I suggested a simple "sed -n -e ...p" you used in
your original was because it could be used to extract not just one
Signed-off-by: lines to store in >actual, to be compared with an
expect that has multiple S-o-b lines and the output is in correct
order, etc.  An elaborate filter that can onlyl give "found/not
found" boolean looks a bit over-engineered for no real gain.

>  # Tests that its two parameters refer to the same revision
>  test_cmp_rev () {
>  	git rev-parse --verify "$1" >expect.rev &&