[RFC PATCH] pack-refs: fail on falsely sorted packed-refs
- From
Max Kirillov <max@max630.net>
- Date
- Jan 30, 2019, 23:13 UTC
- Message-ID
- <20190130231359.23978-1-max@max630.net>
If packed-refs is marked as sorted but not really sorted it causes very hard to comprehend misbehavior of reference resolving - a reference is reported as not found.
As the scope of the issue is not clear, make it visible by failing pack-refs command - the one which would not suffer performance penalty to verify the sortedness - when it encounters not really sorted existing data.
Signed-off-by: Max Kirillov <max@max630.net> --- I happened to have a not really sorted packed-refs file. As you might guess, it was quite wtf-ing experience. It worked, mostly, but there was one branch which just did not resolve, regardless of existing and being presented in for-each-refs output.
I don't know where the corruption came from. I should admit it could even be a manual editing but last time I did it (in that reporitory) was several years ago so it is unlikely.
I am not sure what should be the proper fix. I did a minimal detection, so that it does not go unnoticed. Probably next step would be either fixing in `git fsck` call.
refs/packed-backend.c | 15 +++++++++++++++ t/t3212-pack-refs-broken-sorting.sh | 26 ++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) create mode 100755 t/t3212-pack-refs-broken-sorting.sh
diff --git a/refs/packed-backend.c b/refs/packed-backend.c index c01c7f5901..505f4535b5 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -1088,6 +1088,7 @@ static int write_with_updates(struct packed_ref_store *refs, FILE *out; struct strbuf sb = STRBUF_INIT; char *packed_refs_path; + struct strbuf prev_ref = STRBUF_INIT; if (!is_lock_file_locked(&refs->lock)) BUG("write_with_updates() called while unlocked"); @@ -1137,6 +1138,20 @@ static int write_with_updates(struct packed_ref_store *refs, struct ref_update *update = NULL; int cmp; + if (iter) + { + if (prev_ref.len && strcmp(prev_ref.buf, iter->refname) > 0) + { + strbuf_addf(err, "broken sorting in packed-refs: '%s' > '%s'", + prev_ref.buf, + iter->refname); + goto error; + } + + strbuf_init(&prev_ref, 0); + strbuf_addstr(&prev_ref, iter->refname); + } + if (i >= updates->nr) { cmp = -1; } else { diff --git a/t/t3212-pack-refs-broken-sorting.sh b/t/t3212-pack-refs-broken-sorting.sh new file mode 100755 index 0000000000..37a98a6fb1 --- /dev/null +++ b/t/t3212-pack-refs-broken-sorting.sh @@ -0,0 +1,26 @@ +#!/bin/sh + +test_description='tests for the falsely sorted refs' +. ./test-lib.sh + +test_expect_success 'setup' ' + git commit --allow-empty -m commit && + for num in $(test_seq 10) + do + git branch b$(printf "%02d" $num) || break + done && + git pack-refs --all && + head_object=$(git rev-parse HEAD) && + printf "$head_object refs/heads/b00\\n" >>.git/packed-refs && + git branch b11 +' + +test_expect_success 'off-order branch not found' ' + ! git show-ref --verify --quiet refs/heads/b00 +' + +test_expect_success 'subsequent pack-refs fails' ' + ! git pack-refs --all +' + +test_done
-- 2.19.0.1202.g68e1e8f04e