From 1c03c4d34771db20b78231359caa6fda28e2d9fe Mon Sep 17 00:00:00 2001 From: Michael Haggerty Date: Mon, 22 Jun 2015 16:03:10 +0200 Subject: delete_ref(): use the usual convention for old_sha1 The ref_transaction_update() family of functions use the following convention for their old_sha1 parameters: * old_sha1 == NULL: Don't check the old value at all. * is_null_sha1(old_sha1): Ensure that the reference didn't exist before the transaction. * otherwise: Ensure that the reference had the specified value before the transaction. delete_ref() had a different convention, namely treating is_null_sha1(old_sha1) as "don't care". Change it to adhere to the standard convention to reduce the scope for confusion. Please note that it is now a bug to pass old_sha1=NULL_SHA1 to delete_ref() (because it doesn't make sense to delete a reference that you already know doesn't exist). This is consistent with the behavior of ref_transaction_delete(). Most of the callers of delete_ref() never pass old_sha1=NULL_SHA1 to delete_ref(), and are therefore unaffected by this change. The two exceptions are: * The call in cmd_update_ref(), which passed NULL_SHA1 if the old value passed in on the command line was 0{40} or the empty string. Change that caller to pass NULL in those cases. Arguably, it should be an error to call "update-ref -d" with the old value set to "does not exist", just as it is for the `--stdin` command "delete". But since this usage was accepted until now, continue to accept it. * The call in delete_branches(), which could pass NULL_SHA1 if deleting a broken or symbolic ref. Change it to pass NULL in these cases. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'builtin/update-ref.c') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 160c7ac1d3..6763cf1837 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -422,7 +422,13 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix) if (no_deref) flags = REF_NODEREF; if (delete) - return delete_ref(refname, oldval ? oldsha1 : NULL, flags); + /* + * For purposes of backwards compatibility, we treat + * NULL_SHA1 as "don't care" here: + */ + return delete_ref(refname, + (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL, + flags); else return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL, flags, UPDATE_REFS_DIE_ON_ERR); -- cgit v1.2.1