From: Johannes Schindelin <johannes.schindelin@xxxxxx>
The idea of the magic value "ac4f2ee" in this test is to make the
reworded commit `collide2` have the same shortened ID as the commit
`collide3`.
To port the same idea to the SHA-256 version of Git, we therefore need
another magic value that causes the same collision, but this time with
the SHA-256 version of the commit IDs.
In this patch, we add code guarded by `GIT_TEST_FIND_COLLIDER` to do
exactly that. Essentially, a large number of integers is appended to the
commit message "collide2" to find such a collision. To make it easier to
find such a collision, we reduce the number of digits to 4.
As the tests are no longer dependent on SHA-1, we also rename their
titles to talk about "commit IDs" instead of "SHA-1s".
Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
Signed-off-by: brian m. carlson <sandals@xxxxxxxxxxxxxxxxxxxx>
---
t/t3404-rebase-interactive.sh | 50 ++++++++++++++++++++++++++++-------
1 file changed, 41 insertions(+), 9 deletions(-)
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 4a7d21f898..2fb2c581cb 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -30,6 +30,7 @@ Initial setup:
. "$TEST_DIRECTORY"/lib-rebase.sh
test_expect_success 'setup' '
+ test_oid_init &&
test_commit A file1 &&
test_commit B file1 &&
test_commit C file2 &&
@@ -1250,7 +1251,7 @@ test_expect_success 'rebase -i error on commits with \ in message' '
test_expect_code 1 grep " emp" error
'
-test_expect_success SHA1 'short SHA-1 setup' '
+test_expect_success 'short commit ID setup' '
test_when_finished "git checkout master" &&
git checkout --orphan collide &&
git rm -rf . &&
@@ -1262,23 +1263,54 @@ test_expect_success SHA1 'short SHA-1 setup' '
)
'
-test_expect_success SHA1 'short SHA-1 collide' '
+if test -n "$GIT_TEST_FIND_COLLIDER"
+then
+ author="$(unset test_tick; test_tick; git var GIT_AUTHOR_IDENT)"
+ committer="$(unset test_tick; test_tick; git var GIT_COMMITTER_IDENT)"
+ blob="$(git rev-parse collide2:collide)"
+ from="$(git rev-parse collide1^0)"
+ repl="commit refs/heads/collider-&\\n"
+ repl="${repl}author $author\\ncommitter $committer\\n"
+ repl="${repl}data <<EOF\\ncollide2 &\\nEOF\\n"
+ repl="${repl}from $from\\nM 100644 $blob collide\\n"
+ test_seq 1 32768 | sed "s|.*|$repl|" >script &&
+ git fast-import <script &&
+ git pack-refs &&
+ git for-each-ref >refs &&
+ grep "^$(test_oid t3404_collision)" <refs >matches &&
+ cat matches &&
+ test_line_count -gt 2 matches || {
+ echo "Could not find a collider" >&2
+ exit 1
+ }
+fi
+
+test_expect_success 'short commit ID collide' '
+ test_oid_cache <<-EOF &&
+ # collision-related constants
+ t3404_collision sha1:6bcd
+ t3404_collision sha256:0161
+ t3404_collider sha1:ac4f2ee
+ t3404_collider sha256:16697
+ EOF
test_when_finished "reset_rebase && git checkout master" &&
git checkout collide &&
- colliding_sha1=6bcda37 &&
- test $colliding_sha1 = "$(git rev-parse HEAD | cut -c 1-7)" &&
+ colliding_id=$(test_oid t3404_collision) &&
+ hexsz=$(test_oid hexsz) &&
+ test $colliding_id = "$(git rev-parse HEAD | cut -c 1-4)" &&
+ test_config core.abbrev 4 &&
(
unset test_tick &&
test_tick &&
set_fake_editor &&
- FAKE_COMMIT_MESSAGE="collide2 ac4f2ee" \
+ FAKE_COMMIT_MESSAGE="collide2 $(test_oid t3404_collider)" \
FAKE_LINES="reword 1 break 2" git rebase -i HEAD~2 &&
- test $colliding_sha1 = "$(git rev-parse HEAD | cut -c 1-7)" &&
- grep "^pick $colliding_sha1 " \
+ test $colliding_id = "$(git rev-parse HEAD | cut -c 1-4)" &&
+ grep "^pick $colliding_id " \
.git/rebase-merge/git-rebase-todo.tmp &&
- grep "^pick [0-9a-f]\{40\}" \
+ grep "^pick [0-9a-f]\{$hexsz\}" \
.git/rebase-merge/git-rebase-todo &&
- grep "^pick [0-9a-f]\{40\}" \
+ grep "^pick [0-9a-f]\{$hexsz\}" \
.git/rebase-merge/git-rebase-todo.backup &&
git rebase --continue
) &&
