Re: git update-ref fails to create reference. (bug)
- From
- Martin Ågren <martin.agren@gmail.com>
- Date
- May 4, 2018, 18:26 UTC
- Message-ID
- <20180504182646.7738-1-martin.agren@gmail.com>
- In-Reply-To
- <cced9e2c-7d02-47fd-109a-1185eed13e63@gmail.com>
Hi Rafael,
On 4 May 2018 at 18:28, Rafael Ascensão <rafa.almas@gmail.com> wrote:
Show 12 quoted lines
> While trying to create a pseudo reference named REF pointing to the > empty tree iff it doesn't exist, I stumbled on the following: > > I assume both are valid ways to create such reference: > a) $ echo -e option no-deref\\nupdate REF $(git hash-object -t > tree /dev/null) 0000000000000000000000000000000000000000 | git > update-ref --stdin > b) $ git update-ref --no-deref REF $(git hash-object -t tree > /dev/null) 0000000000000000000000000000000000000000 > > While a) works, b) will throw: > fatal: could not read ref 'REF'
I can reproduce this and I agree with your understanding of what should happen here. The patch below makes this work according to my and your expectations, at least in my command-line testing.
The die("... already exists") could instead be a no-op, trusting that the backend discovers the problem. "die" could also be strbuf_addf(...), I'm just following 2c3aed138 here.
Anyway, that's not where I'm stuck... Regardless of how I try to write tests (in t1400), they just pass beautifully even before this patch. I might be able to look into that more on the weekend. If anyone has ideas, I am all ears. Or if someone feels like picking this up and running with it, feel free.
Martin
diff --git a/refs.c b/refs.c index 8b7a77fe5e..cdb0a5ab29 100644 --- a/refs.c +++ b/refs.c @@ -666,9 +666,12 @@ static int write_pseudoref(const char *pseudoref, const struct object_id *oid, if (old_oid) { struct object_id actual_old_oid; - if (read_ref(pseudoref, &actual_old_oid)) - die("could not read ref '%s'", pseudoref); - if (oidcmp(&actual_old_oid, old_oid)) { + if (read_ref(pseudoref, &actual_old_oid)) { + if (!is_null_oid(old_oid)) + die("could not read ref '%s'", pseudoref); + } else if (is_null_oid(old_oid)) { + die("reference '%s' already exists", pseudoref); + } else if (oidcmp(&actual_old_oid, old_oid)) { strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref); rollback_lock_file(&lock); goto done;
-- 2.17.0.392.g7fa371e468