Re: [PATCH v11 31/41] refs.c: make prune_ref use a transaction to delete the ref

> Ronnie Sahlberg wrote:
>
>> Change prune_ref to delete the ref using a ref transaction. To do this we also
>> need to add a new flag REF_ISPRUNING that will tell the transaction that we
>> do not want to delete this ref from the packed refs.
>
> s/from the packed refs/from packed-refs, nor delete the ref's reflog/
>
> [...]
>> --- a/refs.h
>> +++ b/refs.h
>> @@ -235,6 +235,11 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err);
>>   * The following functions add a reference check or update to a
>>   * ref_transaction.  In all of them, refname is the name of the
>>   * reference to be affected.  The functions make internal copies of
>>   * refname, so the caller retains ownership of the parameter.  flags
>>   * can be REF_NODEREF; it is passed to update_ref_lock().
>>   */
>>
>>  /*
>> + * ref_transaction_update ref_transaction_create and ref_transaction_delete
>> + * all take a flag argument. Currently the only public flag is REF_NODEREF.
>> + * Flag values >= 0x100 are reserved for internal use.
>> + */
>> +/*
>>   * Add a reference update to transaction.  new_sha1 is the value that
>
> The comment right before here already tries to explain the flag argument,
> though it isn't in an obvious place so it's easy to miss.  Maybe the flag
> argument should be explained in the overview documentation for the
> ref_transaction API near the top of the file (but I haven't thought that
> through, so leaving it alone).
>
> How about this as a way to make the reserved flag values easier to
> find when adding new flags?
>
> diff --git i/refs.h w/refs.h
> index 25ac4a9..dee7c8f 100644
> --- i/refs.h
> +++ w/refs.h
> @@ -171,8 +171,17 @@ extern int ref_exists(const char *);
>   */
>  extern int peel_ref(const char *refname, unsigned char *sha1);
>
> -/** Locks any ref (for 'HEAD' type refs). */
> +/*
> + * Flags controlling lock_any_ref_for_update(), ref_transaction_update(),
> + * ref_transaction_create(), etc.
> + * REF_NODEREF: act on the ref directly, instead of dereferencing
> + *              symbolic references.
> + *
> + * Flags >= 0x100 are reserved for internal use.
> + */
>  #define REF_NODEREF    0x01
> +
> +/** Locks any ref (for 'HEAD' type refs). */
>  extern struct ref_lock *lock_any_ref_for_update(const char *refname,
>                                                 const unsigned char *old_sha1,
>                                                 int flags, int *type_p);
> @@ -265,11 +274,6 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err);
>   */
>
>  /*
> - * ref_transaction_update ref_transaction_create and ref_transaction_delete
> - * all take a flag argument. Currently the only public flag is REF_NODEREF.
> - * Flag values >= 0x100 are reserved for internal use.
> - */
> -/*
>   * Add a reference update to transaction.  new_sha1 is the value that
>   * the reference should have after the update, or zeros if it should
>   * be deleted.  If have_old is true, then old_sha1 holds the value