Re: [PATCH v2 06/12] commit: add tests of commit races
From: Stefan Beller <hidden>
Date: 2016-06-15 23:03:48
On Thu, Feb 12, 2015 at 3:12 AM, Michael Haggerty [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Committing involves the following steps: 1. Determine the current value of HEAD (if any). 2. Create the new commit object. 3. Update HEAD. Please note that step 2 can take arbitrarily long, because it might involve the user editing a commit message. If a second process sneaks in a commit during step 2, then the first commit process should fail. This is usually done correctly, because step 3 verifies that HEAD still points at the same commit that it pointed to during step 1. However, if there is a race when creating an *orphan* commit, then the test in step 3 is skipped. Add tests for proper handling of such races. One of the new tests fails. It will be fixed in a moment. Signed-off-by: Michael Haggerty <redacted> --- t/t7516-commit-races.sh | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100755 t/t7516-commit-races.shdiff --git a/t/t7516-commit-races.sh b/t/t7516-commit-races.sh new file mode 100755 index 0000000..08e6a6c --- /dev/null +++ b/t/t7516-commit-races.sh@@ -0,0 +1,33 @@ +#!/bin/sh + +test_description='git commit races' +. ./test-lib.sh + +test_tick
So I am wondering why we need to have a test_tick here. In case we need to pass simulation time after loading the test-lib, we should rather have it inside the test-lib. If we need to pass time specifically for this test (I just don't understand why at this point of execution), then we should move it more to the relevant place inside the &&-chain as all other tests have test_tick inside a test chained up with &&.
+ +test_expect_success 'set up editor' ' + write_script editor <<-\EOF + git commit --allow-empty -m hare + echo tortoise >"$1" + EOF +' + +test_expect_failure 'race to create orphan commit' ' + test_must_fail env EDITOR=./editor git commit --allow-empty && + git show -s --pretty=format:%s >subject && + grep -q hare subject && + test -z "$(git show -s --pretty=format:%P)" +' + +test_expect_success 'race to create non-orphan commit' ' + git checkout --orphan branch && + git commit --allow-empty -m base && + git rev-parse HEAD >base && + test_must_fail env EDITOR=./editor git commit --allow-empty && + git show -s --pretty=format:%s >subject && + grep -q hare subject && + git rev-parse HEAD^ >parent && + test_cmp base parent +' + +test_done -- 2.1.4