From: Junio C Hamano Date: Mon, 15 Jun 2015 18:22:21 GMT Subject: Re: [PATCH v2 03/12] delete_ref(): handle special case more explicitly Message-ID: In-Reply-To: <0c66a6bd6e49b9c28fa3617ee50de746ef4ea9a3.1434206062.git.mhagger@alum.mit.edu> Michael Haggerty writes: > delete_ref() uses a different convention for its old_sha1 parameter > than, say, ref_transaction_delete(): NULL_SHA1 means not to check the > old value. Make this fact a little bit clearer in the code by handling > it in explicit, commented code rather than burying it in a conditional > expression. > > Signed-off-by: Michael Haggerty > --- I think this is a very sensible first step, but I wonder if delete_ref() should be taught the difference between "we do not expect anything" and "we expect it not to exist". > refs.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/refs.c b/refs.c > index b575bb8..f0b6cec 100644 > --- a/refs.c > +++ b/refs.c > @@ -2795,10 +2795,17 @@ int delete_ref(const char *refname, const unsigned char *old_sha1, > struct ref_transaction *transaction; > struct strbuf err = STRBUF_INIT; > > + /* > + * Treat NULL_SHA1 and NULL alike, to mean "we don't care what > + * the old value of the reference was (or even if it didn't > + * exist)": > + */ > + if (old_sha1 && is_null_sha1(old_sha1)) > + old_sha1 = NULL; > + > transaction = ref_transaction_begin(&err); > if (!transaction || > - ref_transaction_delete(transaction, refname, > - (old_sha1 && !is_null_sha1(old_sha1)) ? old_sha1 : NULL, > + ref_transaction_delete(transaction, refname, old_sha1, > flags, NULL, &err) || > ref_transaction_commit(transaction, &err)) { > error("%s", err.buf);