diff options
| -rw-r--r-- | builtin/update-ref.c | 7 | ||||
| -rw-r--r-- | refs.c | 47 | ||||
| -rw-r--r-- | refs.h | 34 |
3 files changed, 67 insertions, 21 deletions
diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 226995f029..3d79a46b03 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -282,7 +282,6 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, { struct strbuf err = STRBUF_INIT; char *refname; - unsigned char new_sha1[20]; unsigned char old_sha1[20]; refname = parse_refname(input, &next); @@ -293,13 +292,11 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, PARSE_SHA1_OLD)) hashclr(old_sha1); - hashcpy(new_sha1, old_sha1); - if (*next != line_termination) die("verify %s: extra input: %s", refname, next); - if (ref_transaction_update(transaction, refname, new_sha1, old_sha1, - update_flags, msg, &err)) + if (ref_transaction_verify(transaction, refname, old_sha1, + update_flags, &err)) die("%s", err.buf); update_flags = 0; @@ -47,10 +47,16 @@ static unsigned char refname_disposition[256] = { #define REF_ISPRUNING 0x04 /* + * Used as a flag in ref_update::flags when the reference should be + * updated to new_sha1. + */ +#define REF_HAVE_NEW 0x08 + +/* * Used as a flag in ref_update::flags when old_sha1 should be * checked. */ -#define REF_HAVE_OLD 0x08 +#define REF_HAVE_OLD 0x10 /* * Try to read one refname component from the front of refname. @@ -3577,10 +3583,17 @@ int for_each_reflog(each_ref_fn fn, void *cb_data) * not exist before update. */ struct ref_update { + /* + * If (flags & REF_HAVE_NEW), set the reference to this value: + */ unsigned char new_sha1[20]; + /* + * If (flags & REF_HAVE_OLD), check that the reference + * previously had this value: + */ unsigned char old_sha1[20]; /* - * One or more of REF_HAVE_OLD, REF_NODEREF, + * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF, * REF_DELETING, and REF_ISPRUNING: */ unsigned int flags; @@ -3665,7 +3678,7 @@ int ref_transaction_update(struct ref_transaction *transaction, if (transaction->state != REF_TRANSACTION_OPEN) die("BUG: update called for transaction that is not open"); - if (!is_null_sha1(new_sha1) && + if (new_sha1 && !is_null_sha1(new_sha1) && check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { strbuf_addf(err, "refusing to update ref with bad name %s", refname); @@ -3673,7 +3686,10 @@ int ref_transaction_update(struct ref_transaction *transaction, } update = add_update(transaction, refname); - hashcpy(update->new_sha1, new_sha1); + if (new_sha1) { + hashcpy(update->new_sha1, new_sha1); + flags |= REF_HAVE_NEW; + } if (old_sha1) { hashcpy(update->old_sha1, old_sha1); flags |= REF_HAVE_OLD; @@ -3709,6 +3725,19 @@ int ref_transaction_delete(struct ref_transaction *transaction, flags, msg, err); } +int ref_transaction_verify(struct ref_transaction *transaction, + const char *refname, + const unsigned char *old_sha1, + unsigned int flags, + struct strbuf *err) +{ + if (!old_sha1) + die("BUG: verify called with old_sha1 set to NULL"); + return ref_transaction_update(transaction, refname, + NULL, old_sha1, + flags, NULL, err); +} + int update_ref(const char *action, const char *refname, const unsigned char *sha1, const unsigned char *oldval, unsigned int flags, enum action_on_err onerr) @@ -3797,7 +3826,7 @@ int ref_transaction_commit(struct ref_transaction *transaction, struct ref_update *update = updates[i]; unsigned int flags = update->flags; - if (is_null_sha1(update->new_sha1)) + if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) flags |= REF_DELETING; update->lock = lock_ref_sha1_basic( update->refname, @@ -3819,8 +3848,9 @@ int ref_transaction_commit(struct ref_transaction *transaction, /* Perform updates first so live commits remain referenced */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; + int flags = update->flags; - if (!is_null_sha1(update->new_sha1)) { + if ((flags & REF_HAVE_NEW) && !is_null_sha1(update->new_sha1)) { if (write_ref_sha1(update->lock, update->new_sha1, update->msg)) { update->lock = NULL; /* freed by write_ref_sha1 */ @@ -3836,14 +3866,15 @@ int ref_transaction_commit(struct ref_transaction *transaction, /* Perform deletes now that updates are safely completed */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; + int flags = update->flags; - if (update->lock) { + if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) { if (delete_ref_loose(update->lock, update->type, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } - if (!(update->flags & REF_ISPRUNING)) + if (!(flags & REF_ISPRUNING)) string_list_append(&refs_to_delete, update->lock->ref_name); } @@ -263,14 +263,19 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err); */ /* - * Add a reference update to transaction. new_sha1 is the value that - * the reference should have after the update, or null_sha1 if it should - * be deleted. If old_sha1 is non-NULL, then it is the value - * that the reference should have had before the update, or null_sha1 if - * it must not have existed beforehand. - * Function returns 0 on success and non-zero on failure. A failure to update - * means that the transaction as a whole has failed and will need to be - * rolled back. + * Add a reference update to transaction. new_sha1 is the value that + * the reference should have after the update, or null_sha1 if it + * should be deleted. If new_sha1 is NULL, then the reference is not + * changed at all. old_sha1 is the value that the reference must have + * before the update, or null_sha1 if it must not have existed + * beforehand. The old value is checked after the lock is taken to + * prevent races. If the old value doesn't agree with old_sha1, the + * whole transaction fails. If old_sha1 is NULL, then the previous + * value is not checked. + * + * Return 0 on success and non-zero on failure. Any failure in the + * transaction means that the transaction as a whole has failed and + * will need to be rolled back. */ int ref_transaction_update(struct ref_transaction *transaction, const char *refname, @@ -309,6 +314,19 @@ int ref_transaction_delete(struct ref_transaction *transaction, struct strbuf *err); /* + * Verify, within a transaction, that refname has the value old_sha1, + * or, if old_sha1 is null_sha1, then verify that the reference + * doesn't exist. old_sha1 must be non-NULL. Function returns 0 on + * success and non-zero on failure. A failure to verify means that the + * transaction as a whole has failed and will need to be rolled back. + */ +int ref_transaction_verify(struct ref_transaction *transaction, + const char *refname, + const unsigned char *old_sha1, + unsigned int flags, + struct strbuf *err); + +/* * Commit all of the changes that have been queued in transaction, as * atomically as possible. * |