Patrick Steinhardt writes: >> +symref-verify:: >> + Verify symbolic against but do not change it. >> + If is missing, the ref must not exist. Can only be >> + used in `no-deref` mode. > > Should this say "is zero or missing", like the comment for "verify" > does? > We don't allow users to enter OID here, we do convert it to zero OID internally. But the user input is expected to be old_ref or nothing. > [snip] >> @@ -297,11 +321,48 @@ static void parse_cmd_verify(struct ref_transaction *transaction, >> die("verify %s: extra input: %s", refname, next); >> >> if (ref_transaction_verify(transaction, refname, &old_oid, >> - update_flags, &err)) >> + NULL, update_flags, &err)) >> + die("%s", err.buf); >> + >> + update_flags = default_flags; >> + free(refname); >> + strbuf_release(&err); >> +} >> + >> +static void parse_cmd_symref_verify(struct ref_transaction *transaction, >> + const char *next, const char *end) >> +{ >> + struct strbuf err = STRBUF_INIT; >> + struct object_id old_oid; >> + char *refname, *old_ref; >> + >> + if (!(update_flags & REF_NO_DEREF)) >> + die("symref-verify: cannot operate with deref mode"); > > This feels quite restrictive to me. Wouldn't it be preferable to simply > ignore `REF_NO_DEREF` here? It basically means that this command can't > ever be used in a normal `git update-ref --stdin` session. > We do support 'option' with the '--stdin' flag. So technically a user should be able to do. $ git update-ref --stdin no-deref symref-verify refs/heads/symref refs/heads/master update-ref refs/heads/branch 0b3b55ad0e593ead604f80fe3f621239b34cce7e I guess we could make it implicit, but I thought it's better to keep it explicit so the user knows that there is no dereferencing taking place here, eventhough the default option is to dereference. [snip] >> >> update->flags = flags; >> >> - if (flags & REF_HAVE_NEW) >> - oidcpy(&update->new_oid, new_oid); >> - if (flags & REF_HAVE_OLD) >> - oidcpy(&update->old_oid, old_oid); >> + /* >> + * The ref values are to be considered over the oid values when we're >> + * doing symref operations. >> + */ > > I feel like this is a statement that should be backed up by a deeper > explanation of why that is. I'm still wondering here why we cannot > assert that the old value is an object ID when I want to update it to a > symref, or alternatively why it would even be possible to have both > `REF_SYMREF_UPDATE` and a set of other, incompatible fields set. It > feels like this should be a `BUG()` instead if this is supposedly an > unsupported configuration rather than silently ignoring it. > > In any case, I feel like it would be easier to reason about if this was > introduced together with the actual user. As far as I can see this code > shouldn't ever be hit for "verify-symref", right? Currently, the reader > is forced to figure out what is and isn't related to the new command. > I've changed this now to no longer have this condition and also added 'BUG' for cases where both old_{ref,target} and new_{ref,target} exist. [snip] >> @@ -2464,8 +2495,7 @@ static int lock_ref_for_update(struct files_ref_store *refs, >> struct strbuf *err) >> { >> struct strbuf referent = STRBUF_INIT; >> - int mustexist = (update->flags & REF_HAVE_OLD) && >> - !is_null_oid(&update->old_oid); >> + int mustexist = (update->flags & REF_HAVE_OLD) && !is_null_oid(&update->old_oid); > > This change is a no-op, right? If so, let's rather drop it. > Yeah, will do. >> int ret = 0; >> struct ref_lock *lock; >> >> @@ -2514,6 +2544,18 @@ static int lock_ref_for_update(struct files_ref_store *refs, >> ret = TRANSACTION_GENERIC_ERROR; >> goto out; >> } >> + } >> + >> + /* >> + * For symref verification, we need to check the referent value >> + * rather than the oid. If we're dealing with regular refs or we're >> + * verifying a dereferenced symref, we then check the oid. >> + */ >> + if (update->flags & REF_SYMREF_UPDATE && update->old_ref) { >> + if (check_old_ref(update, referent.buf, err)) { >> + ret = TRANSACTION_GENERIC_ERROR; >> + goto out; >> + } >> } else if (check_old_oid(update, &lock->old_oid, err)) { >> ret = TRANSACTION_GENERIC_ERROR; >> goto out; >> diff --git a/refs/refs-internal.h b/refs/refs-internal.h >> index 4c5fe02687..21c6b940d8 100644 >> --- a/refs/refs-internal.h >> +++ b/refs/refs-internal.h >> @@ -749,4 +749,11 @@ void base_ref_store_init(struct ref_store *refs, struct repository *repo, >> */ >> struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_store *store); >> >> +/* >> + * Helper function to check if the new value is null, this >> + * takes into consideration that the update could be a regular >> + * ref or a symbolic ref. >> + */ >> +int null_new_value(struct ref_update *update); > > When adding it to the header we should probably prefix this to avoid > name collisions. `ref_update_is_null_new_value()` might be a mouth full, > but feels preferable to me. > Makes sense. >> #endif /* REFS_REFS_INTERNAL_H */ >> diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c >> index 6104471199..7a03922c7b 100644 >> --- a/refs/reftable-backend.c >> +++ b/refs/reftable-backend.c >> @@ -938,7 +938,28 @@ static int reftable_be_transaction_prepare(struct ref_store *ref_store, >> * individual refs. But the error messages match what the files >> * backend returns, which keeps our tests happy. >> */ >> - if (u->flags & REF_HAVE_OLD && !oideq(¤t_oid, &u->old_oid)) { >> + if ((u->flags & REF_HAVE_OLD) && >> + (u->flags & REF_SYMREF_UPDATE) && >> + u->old_ref) { >> + if (strcmp(referent.buf, u->old_ref)) { > > s/ / / > >> + if (!strcmp(u->old_ref, "")) >> + strbuf_addf(err, "cannot lock ref '%s': " >> + "reference already exists", >> + original_update_refname(u)); >> + else if (!strcmp(referent.buf, "")) >> + strbuf_addf(err, "cannot lock ref '%s': " >> + "reference is missing but expected %s", >> + original_update_refname(u), >> + u->old_ref); >> + else >> + strbuf_addf(err, "cannot lock ref '%s': " >> + "is at %s but expected %s", >> + original_update_refname(u), >> + referent.buf, u->old_ref); > > I'd use better-matching error messages here. I know that we talk about > "cannot lock ref" in the next branch, as well. But the only reason we > did this is to have the same error messages as the "files" backend. > Semantically, those errors don't make much sense as the "reftable" > backend never locks specific refs, but only the complete stack. > Fair enough, will change. >> + ret = -1; >> + goto done; >> + } >> + } else if (u->flags & REF_HAVE_OLD && !oideq(¤t_oid, &u->old_oid)) { >> if (is_null_oid(&u->old_oid)) >> strbuf_addf(err, _("cannot lock ref '%s': " >> "reference already exists"), >> diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh >> index ec3443cc87..d8ffda4096 100755 >> --- a/t/t1400-update-ref.sh >> +++ b/t/t1400-update-ref.sh >> @@ -890,17 +890,23 @@ test_expect_success 'stdin update/create/verify combination works' ' >> ' >> >> test_expect_success 'stdin verify succeeds for correct value' ' >> + test-tool ref-store main for-each-reflog-ent $m >before && >> git rev-parse $m >expect && >> echo "verify $m $m" >stdin && >> git update-ref --stdin > git rev-parse $m >actual && >> - test_cmp expect actual >> + test_cmp expect actual && >> + test-tool ref-store main for-each-reflog-ent $m >after && >> + test_cmp before after >> ' >> >> test_expect_success 'stdin verify succeeds for missing reference' ' >> + test-tool ref-store main for-each-reflog-ent $m >before && >> echo "verify refs/heads/missing $Z" >stdin && >> git update-ref --stdin > - test_must_fail git rev-parse --verify -q refs/heads/missing >> + test_must_fail git rev-parse --verify -q refs/heads/missing && >> + test-tool ref-store main for-each-reflog-ent $m >after && >> + test_cmp before after >> ' > > The updated tests merely assert that the refs didn't change, right? > Yes, also that we didn't add anything unexpected to the reflog. >> test_expect_success 'stdin verify treats no value as missing' ' >> @@ -1641,4 +1647,74 @@ test_expect_success PIPE 'transaction flushes status updates' ' >> test_cmp expected actual >> ' >> >> +create_stdin_buf () >> +{ > > The curly brace should go on the same line as the function name. > Right, will change. >> + if test "$1" = "-z" >> + then >> + shift >> + printf "$F" "$@" >stdin >> + else >> + echo "$@" >stdin >> + fi >> +} >> + >> +for type in "" "-z" >> +do > > We should probably indent all of the tests to make it easier to see that > they run in a loop. > > Patrick > I was a bit confused about this, I saw smaller tests with loops indented, while some larger ones not indented. I think its better to do so too, let me do that.