prune_ref(): call `ref_transaction_add_update()` directly

`prune_ref()` needs to use the `REF_ISPRUNING` flag, but we want to
make that flag private to the files backend. So instead of calling
`ref_transaction_delete()`, which is a public function and therefore
shouldn't allow the `REF_ISPRUNING` flag, change `prune_ref()` to call
`ref_transaction_add_update()`, which is private to the refs
module. (Note that we don't need any of the other services provided by
`ref_transaction_delete()`.)

This allows us to change `ref_transaction_update()` to reject the
`REF_ISPRUNING` flag. Do so by adjusting
`REF_TRANSACTION_UPDATE_ALLOWED_FLAGS`. Also add parentheses to its
definition to avoid potential future mishaps.

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

1 files changed, 1 insertions, 3 deletions

diff --git a/refs.h b/refs.h
index 15fd419c7..4ffef9502 100644
--- a/refs.h
+++ b/refs.h
@@ -349,9 +349,7 @@ int refs_pack_refs(struct ref_store *refs, unsigned int flags);
  * Flags that can be passed in to ref_transaction_update
  */
 #define REF_TRANSACTION_UPDATE_ALLOWED_FLAGS \
-	REF_ISPRUNING |                      \
-	REF_FORCE_CREATE_REFLOG |            \
-	REF_NODEREF
+	(REF_NODEREF | REF_FORCE_CREATE_REFLOG)
 
 /*
  * Setup reflog before using. Fill in err and return -1 on failure.