delete_ref(): handle special case more explicitly

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 <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/refs.c b/refs.c
index 7b2ca2ca364fba488e775603eb93147099146de8..9b7bdd4198efe43d4eec0c149e7d3127ffd354cc 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -2807,10 +2807,17 @@ 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);