Add a "set -o pipefail" test mode to the test suite to detect failures
in "git" its output is fed directly to a pipe. Doing so is a pattern
we discourage[1] in the test suite, but we've got plenty of tests like
that. Now we can reliably detect those failures.
There was a previous attempt in [2] to add such a test mode, but as
noted by Jeff King in [3] adding it is a matter of peeing against the
wind with current bash semantics of failing on SIGPIPE.
This series relies on a patch of mine to bash, which I'm submitting
upstream, while not breaking anything for vanilla bash users. They
won't have GIT_TEST_PIPEFAIL turned on for them, and will only get
breakages if they turn it on explicitly with "GIT_TEST_PIPEFAIL=true".
Vanilla bash ignores SIGPIPE under "set -e" since version 3.1. It's
only under "set -o pipefail" (added in 3.2) that it doesn't take
account of SIGPIPE, in a seeming omission nobody bothered to fix yet.
Patching bash[4] with:
diff --git a/jobs.c b/jobs.c
index a581f305..fa5de82a 100644
--- a/jobs.c
+++ b/jobs.c
@@ -2851,8 +2851,14 @@ raw_job_exit_status (job)
p = jobs[job]->pipe;
do
{
- if (WSTATUS (p->status) != EXECUTION_SUCCESS)
- fail = WSTATUS(p->status);
+ if (WSTATUS (p->status) != EXECUTION_SUCCESS
+#if defined (DONT_REPORT_SIGPIPE)
+ && WTERMSIG (p->status) != SIGPIPE
+#endif
+ )
+ {
+ fail = WSTATUS(p->status);
+ }
p = p->next;
}
while (p != jobs[job]->pipe);
Makes it useful for something like the git test suite.
Under this test mode we only tests we need to skip those tests which
are explicitly testing that a piped command returned SIGPIPE. Those
tests will now return 0 instead of an exit code indicating SIGPIPE.
Forcing the mode to run under vanilla bash with
"GIT_TEST_PIPEFAIL=true" doesn't fail any tests for me, except the
test in t0000-basic.sh which explicitly checks for the desired
pipefail semantics. However, as Jeff noted in [3] that absence of
failure isn't reliable. I might not see some of the failures due to
the racy nature of how vanilla "set -o pipefail" interacts with *nix
pipe semantics.
1. a378fee5b0 (Documentation: add shell guidelines, 2018-10-05)
2. https://lore.kernel.org/git/cover.1573779465.git.liu.denton@xxxxxxxxx/
3. https://lore.kernel.org/git/20191115040909.GA21654@xxxxxxxxxxxxxxxxxxxxx/
4. https://github.com/bminor/bash/compare/master...avar:avar/ignore-sigterm-and-sigpipe-on-pipe-fail
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
t/README | 5 +++++
t/t0000-basic.sh | 4 ++++
t/t0005-signals.sh | 4 ++--
t/t3600-rm.sh | 5 ++++-
t/t5000-tar-tree.sh | 2 +-
t/t9902-completion.sh | 5 +++++
t/test-lib.sh | 29 +++++++++++++++++++++++++++++
7 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/t/README b/t/README
index c730a70770..cecc00442d 100644
--- a/t/README
+++ b/t/README
@@ -439,6 +439,11 @@ GIT_TEST_DEFAULT_HASH=<hash-algo> specifies which hash algorithm to
use in the test scripts. Recognized values for <hash-algo> are "sha1"
and "sha256".
+GIT_TEST_PIPEFAIL=<boolean>, when true, run 'set -o pipefail' to catch
+failures in commands that aren't the last in a pipe. Defaults to true
+on bash versions which know how to ignore SIGPIPE failures under the
+'set -o pipefail' mode.
+
Naming Tests
------------
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index f4ba2e8c85..38e04b9ce0 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -1326,4 +1326,8 @@ test_expect_success 'test_must_fail rejects a non-git command with env' '
grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
'
+test_expect_success BASH_SET_O_PIPEFAIL 'our bash under "set -o pipefail" mode ignores SIGPIPE failures' '
+ yes | head -n 1 | true
+'
+
test_done
diff --git a/t/t0005-signals.sh b/t/t0005-signals.sh
index 4c214bd11c..cc5784a274 100755
--- a/t/t0005-signals.sh
+++ b/t/t0005-signals.sh
@@ -40,12 +40,12 @@ test_expect_success 'create blob' '
git add file
'
-test_expect_success !MINGW 'a constipated git dies with SIGPIPE' '
+test_expect_success !MINGW,!BASH_SET_O_PIPEFAIL 'a constipated git dies with SIGPIPE' '
OUT=$( ((large_git; echo $? 1>&3) | :) 3>&1 ) &&
test_match_signal 13 "$OUT"
'
-test_expect_success !MINGW 'a constipated git dies with SIGPIPE even if parent ignores it' '
+test_expect_success !MINGW,!BASH_SET_O_PIPEFAIL 'a constipated git dies with SIGPIPE even if parent ignores it' '
OUT=$( ((trap "" PIPE; large_git; echo $? 1>&3) | :) 3>&1 ) &&
test_match_signal 13 "$OUT"
'
diff --git a/t/t3600-rm.sh b/t/t3600-rm.sh
index 4f7e62d05c..7b5d92add5 100755
--- a/t/t3600-rm.sh
+++ b/t/t3600-rm.sh
@@ -251,7 +251,10 @@ test_expect_success 'choking "git rm" should not let it die with cruft' '
i=$(( $i + 1 ))
done | git update-index --index-info &&
OUT=$( ((trap "" PIPE; git rm -n "some-file-*"; echo $? 1>&3) | :) 3>&1 ) &&
- test_match_signal 13 "$OUT" &&
+ if ! test_have_prereq BASH_SET_O_PIPEFAIL
+ then
+ test_match_signal 13 "$OUT"
+ fi &&
test_path_is_missing .git/index.lock
'
diff --git a/t/t5000-tar-tree.sh b/t/t5000-tar-tree.sh
index 3ebb0d3b65..3adcbce84c 100755
--- a/t/t5000-tar-tree.sh
+++ b/t/t5000-tar-tree.sh
@@ -416,7 +416,7 @@ test_expect_success LONG_IS_64BIT 'set up repository with huge blob' '
# We expect git to die with SIGPIPE here (otherwise we
# would generate the whole 64GB).
-test_expect_success LONG_IS_64BIT 'generate tar with huge size' '
+test_expect_success LONG_IS_64BIT,!BASH_SET_O_PIPEFAIL 'generate tar with huge size' '
{
git archive HEAD
echo $? >exit-code
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index c4a7758409..947294bebb 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -7,6 +7,11 @@ test_description='test bash completion'
. ./lib-bash.sh
+if test -n "$GIT_TEST_PIPEFAIL_TRUE"
+then
+ set +o pipefail
+fi
+
complete ()
{
# do nothing
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 9fa7c1d0f6..118dc80ffc 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -36,6 +36,31 @@ then
fi
GIT_BUILD_DIR="$TEST_DIRECTORY"/..
+# Does "set -o pipefail" on this bash version handle SIGPIPE? Use it!
+. "$TEST_DIRECTORY/lib-bash-detection.sh"
+GIT_TEST_PIPEFAIL_TRUE=
+GIT_TEST_PIPEFAIL_DEFAULT=false
+if test -n "$TEST_SH_IS_BIN_BASH" &&
+ $BASH -c 'set -eo pipefail; yes | head -n 1 >/dev/null'
+then
+ GIT_TEST_PIPEFAIL_DEFAULT=true
+fi
+# We're too early for test_bool_env
+if git env--helper --type=bool --default="$GIT_TEST_PIPEFAIL_DEFAULT" \
+ --exit-code GIT_TEST_PIPEFAIL
+then
+ set -o pipefail
+
+ # Only "set -o pipefail" in the main test scripts, not any
+ # sub-programs we spawn.
+ GIT_TEST_PIPEFAIL=
+ export GIT_TEST_PIPEFAIL
+
+ # For the convenience of the prereq for it.
+ GIT_TEST_PIPEFAIL_TRUE=true
+ export GIT_TEST_PIPEFAIL_TRUE
+fi
+
# If we were built with ASAN, it may complain about leaks
# of program-lifetime variables. Disable it by default to lower
# the noise level. This needs to happen at the start of the script,
@@ -1552,6 +1577,10 @@ test_lazy_prereq PIPE '
rm -f testfifo && mkfifo testfifo
'
+test_lazy_prereq BASH_SET_O_PIPEFAIL '
+ test -n "$GIT_TEST_PIPEFAIL_TRUE"
+'
+
test_lazy_prereq SYMLINKS '
# test whether the filesystem supports symbolic links
ln -s x y && test -h y
--
2.29.2.222.g5d2a92d10f8
