[PATCH 2/3] t3404: rebase: interactive: demonstrate short SHA-1 collision
- From
Eric Sunshine <sunshine@sunshineco.com>
- Date
- Aug 12, 2013, 04:07 UTC
- Message-ID
- <1376280459-55188-3-git-send-email-sunshine@sunshineco.com>
- In-Reply-To
- <1376280459-55188-1-git-send-email-sunshine@sunshineco.com>
The 'todo' sheet for interactive rebase shows abbreviated SHA-1's and then performs its operations upon those shortened values. This can lead to an abort if the SHA-1 of a reworded or edited commit is no longer unique within the abbreviated SHA-1 space and a subsequent SHA-1 in the todo list has the same abbreviated value.
For example:
edit f00dfad first pick badbeef second
If, after editing, the new SHA-1 of "first" is now badbeef5ba78983324dff5265c80c4490d5a809a, then the subsequent 'pick badbeef second' will fail since badbeef is no longer a unique SHA-1 abbreviation:
error: short SHA1 badbeef is ambiguous. fatal: Needed a single revision Invalid commit name: badbeef
Demonstrate this problem with a couple of specially crafted commits which initially have distinct abbreviated SHA-1's, but for which the abbreviated SHA-1's collide after a simple rewording of the first commit's message.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> --- t/t3404-rebase-interactive.sh | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh index af141be..e5ebec6 100755 --- a/t/t3404-rebase-interactive.sh +++ b/t/t3404-rebase-interactive.sh @@ -977,4 +977,21 @@ test_expect_success 'rebase -i with --strategy and -X' ' test $(cat file1) = Z ' +test_expect_success 'short SHA-1 setup' ' + test_when_finished "git checkout master" && + git checkout --orphan collide && + git rm -rf . && + unset test_tick && + test_commit collide1 collide && + test_commit --notick collide2 collide && + test_commit --notick "collide3 115158b5" collide collide3 collide3 +' + +test_expect_failure 'short SHA-1 collide' ' + test_when_finished "reset_rebase && git checkout master" && + git checkout collide && + FAKE_COMMIT_MESSAGE="collide2 815200e" \ + FAKE_LINES="reword 1 2" git rebase -i HEAD~2 +' + test_done
-- 1.8.4.rc2.460.ga591f4a