Re: [PATCH] Expect the exit code of builtin checkout to be in portable range

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

Alex Riesen <raa.lkml@gmail.com> writes:

> This allows crashes to be noticed at least in bash and dash, which put
> the signal which terminated the command in its exit status.
>
> Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
> ---
>
> Alex Riesen, Thu, Feb 28, 2008 17:30:47 +0100:
>> Noticed in t2008, which actually passed, but silently removed
>> core-files (I saw segfaults in syslog) and did not properly check the
>> exit code.  The change for the t2008 comes as seperate patch, but it
>> should be noted that "! command" is *not* how you check for a command
>> to have failed. It could have crashed.
>
> So we'd better check the exit status in failure tests.
> Like this, for instance

Yeah, very well spotted, although I would have liked it if this
were caught before it hit 'master'.

I think we want a helper shell function to fix potentially many
other uses of "! git-command" construct, so how about doing it
this way?

---
 t/t2008-checkout-subdir.sh |    8 ++++----
 t/test-lib.sh              |   17 +++++++++++++++++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/t/t2008-checkout-subdir.sh b/t/t2008-checkout-subdir.sh
index 4a723dc..3e098ab 100755
--- a/t/t2008-checkout-subdir.sh
+++ b/t/t2008-checkout-subdir.sh
@@ -68,15 +68,15 @@ test_expect_success 'checkout with simple prefix' '
 '
 
 test_expect_success 'relative path outside tree should fail' \
-	'! git checkout HEAD -- ../../Makefile'
+	'test_must_fail git checkout HEAD -- ../../Makefile'
 
 test_expect_success 'incorrect relative path to file should fail (1)' \
-	'! git checkout HEAD -- ../file0'
+	'test_must_fail git checkout HEAD -- ../file0'
 
 test_expect_success 'incorrect relative path should fail (2)' \
-	'( cd dir1 && ! git checkout HEAD -- ./file0 )'
+	'( cd dir1 && test_must_fail git checkout HEAD -- ./file0 )'
 
 test_expect_success 'incorrect relative path should fail (3)' \
-	'( cd dir1 && ! git checkout HEAD -- ../../file0 )'
+	'( cd dir1 && test_must_fail git checkout HEAD -- ../../file0 )'
 
 test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 83889c4..90df619 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -270,6 +270,23 @@ test_expect_code () {
 	echo >&3 ""
 }
 
+# This is not among top-level (test_expect_success | test_expect_failure)
+# but is a prefix that can be used in the test script, like:
+#
+#	test_expect_success 'complain and die' '
+#           do something &&
+#           do something else &&
+#	    test_must_fail git checkout ../outerspace
+#	'
+#
+# Writing this as "! git checkout ../outerspace" is wrong, because
+# the failure could be due to a segv.  We want a controlled failure.
+
+test_must_fail () {
+	"$@"
+	test $? -gt 0 -a $? -le 128
+}
+
 # Most tests can use the created repository, but some may need to create more.
 # Usage: test_create_repo <directory>
 test_create_repo () {