diff mbox series

[v2] convert: fail gracefully upon missing clean cmd on required filter

Message ID ead5b3145c0cbf726c2fe06f5c95536373c85265.1614354223.git.matheus.bernardino@usp.br (mailing list archive)
State Accepted
Commit 6fab35f748651c408cf300d871d24c920108d94f
Headers show
Series [v2] convert: fail gracefully upon missing clean cmd on required filter | expand

Commit Message

Matheus Tavares Bernardino Feb. 26, 2021, 4:23 p.m. UTC
The gitattributes documentation mentions that either the clean cmd or
the smudge cmd can be left unspecified in a filter definition. However,
when the filter is marked as 'required', the absence of any one of these
two should be treated as an error. Git already fails under these
circumstances, but not always in a pleasant way: omitting a clean cmd in
a required filter triggers an assertion error which leaves the user with
a quite verbose message:

git: convert.c:1459: convert_to_git_filter_fd: Assertion "ca.drv->clean || ca.drv->process" failed.

This assertion is not really necessary, as the apply_filter() call below
it already performs the same check. And when this condition is not met,
the function returns 0, making the caller die() with a much nicer
message. (Also note that die()-ing here is the right behavior as
`would_convert_to_git_filter_fd() == true` is a precondition to use
convert_to_git_filter_fd(), and the former is only true when the filter
is required.) So remove the assertion and add two regression tests to
make sure that git fails nicely when either the smudge or clean command
is missing on a required filter.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
---

Changes since v1: didn't remove the first assertion and adjusted the
commit message. Thanks for catching that, Martin.

 convert.c             |  1 -
 t/t0021-conversion.sh | 24 ++++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

Comments

Martin Ă…gren Feb. 28, 2021, 8:01 p.m. UTC | #1
On Fri, 26 Feb 2021 at 17:24, Matheus Tavares <matheus.bernardino@usp.br> wrote:
> This assertion is not really necessary, as the apply_filter() call below
> it already performs the same check. And when this condition is not met,

> -       assert(ca.drv->clean || ca.drv->process);

FWIW, this LGTM.

> +       test_i18ngrep "fatal: test.ac: clean filter .absentclean. failed" stderr

> +       test_i18ngrep "fatal: test.as: smudge filter absentsmudge failed" stderr

(Funny how these two error messages differ in quoting. That's obviously
not anything your patch needs to fix.)

Martin
diff mbox series

Patch

diff --git a/convert.c b/convert.c
index ee360c2f07..2c2c2adf61 100644
--- a/convert.c
+++ b/convert.c
@@ -1456,7 +1456,6 @@  void convert_to_git_filter_fd(const struct index_state *istate,
 	convert_attrs(istate, &ca, path);
 
 	assert(ca.drv);
-	assert(ca.drv->clean || ca.drv->process);
 
 	if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL, NULL))
 		die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index e828ee964c..4f8415d419 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -257,6 +257,30 @@  test_expect_success 'required filter clean failure' '
 	test_must_fail git add test.fc
 '
 
+test_expect_success 'required filter with absent clean field' '
+	test_config filter.absentclean.smudge cat &&
+	test_config filter.absentclean.required true &&
+
+	echo "*.ac filter=absentclean" >.gitattributes &&
+
+	echo test >test.ac &&
+	test_must_fail git add test.ac 2>stderr &&
+	test_i18ngrep "fatal: test.ac: clean filter .absentclean. failed" stderr
+'
+
+test_expect_success 'required filter with absent smudge field' '
+	test_config filter.absentsmudge.clean cat &&
+	test_config filter.absentsmudge.required true &&
+
+	echo "*.as filter=absentsmudge" >.gitattributes &&
+
+	echo test >test.as &&
+	git add test.as &&
+	rm -f test.as &&
+	test_must_fail git checkout -- test.as 2>stderr &&
+	test_i18ngrep "fatal: test.as: smudge filter absentsmudge failed" stderr
+'
+
 test_expect_success 'filtering large input to small output should use little memory' '
 	test_config filter.devnull.clean "cat >/dev/null" &&
 	test_config filter.devnull.required true &&