Subject: Re: [PATCH v3 5/7] refs: add safe_create_reflog function

From: Junio C Hamano <[email-masked]>
Date: Fri, 26 Jun 2015 15:12:58 -0700

David Turner <[email-masked]> writes:

> Make log_ref_setup private, and add public safe_create_reflog which
> calls log_ref_setup.
>
> In a moment, we will use safe_create_reflog to add reflog creation
> commands to git-reflog.
>
> Signed-off-by: David Turner <[email-masked]>
> ---

> @@ -629,9 +628,8 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
>  				ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
>  				temp = log_all_ref_updates;
>  				log_all_ref_updates = 1;
> -				ret = log_ref_setup(ref_name, &log_file, &err);
> +				ret = safe_create_reflog(ref_name, &err, 0);
>  				log_all_ref_updates = temp;
> -				strbuf_release(&log_file);

What the result of applying this patch does around here is
incoherent, isn't it?  I do understand and agree that adding the
"force-create" argument to safe_create_reflog() is a good idea, but
then I do not think you need to temporarily set log-all-ref-updates
while calling it (and revert it afterwards).  Not having to do that
is the whole point of "force-create", isn't it?

> diff --git a/refs.c b/refs.c
> index dff91cf..7519dac 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -3123,11 +3123,12 @@ static int should_autocreate_reflog(const char *refname)
>  	return starts_with(refname, "refs/heads/") ||
>  		starts_with(refname, "refs/remotes/") ||
>  		starts_with(refname, "refs/notes/") ||
> +		!strcmp(refname, "refs/stash") ||
>  		!strcmp(refname, "HEAD");
>  }

This change is *not* part of creating safe-create-reflog.

It may be part of "allowing us to use safe_create_reflog() to manage
stash", but I'd imagine that a new "reflog create" command should
ignore log-all-ref-updates settings (after all, the end user is
explicitly telling us to create one by issuing a command), so I
doubt it matters if 'stash' is on the auto-create list.

>  /* This function will fill in *err and return -1 on failure */
> -int log_ref_setup(const char *refname, struct strbuf *sb_logfile, struct strbuf *err)
> +static int log_ref_setup(const char *refname, struct strbuf *sb_logfile, struct strbuf *err, int force_create)
>  {
>  	int logfd, oflags = O_APPEND | O_WRONLY;
>  	char *logfile;
> @@ -3136,7 +3137,8 @@ int log_ref_setup(const char *refname, struct strbuf *sb_logfile, struct strbuf
>  	logfile = sb_logfile->buf;
>  	/* make sure the rest of the function can't change "logfile" */
>  	sb_logfile = NULL;
> -	if (log_all_ref_updates && should_autocreate_reflog(refname)) {
> +	if (log_all_ref_updates &&
> +	    (force_create || should_autocreate_reflog(refname))) {

With this patch, force_create is used as "we are throwing you an
unusual name that do not automatically get a reflog when log-all is
set, and we are overriding that selection-by-name aspect of auto
creation" but does not defeat log-all settings.  Is that intended?

If somebody asks safe_create_reflog() to create a reflog and passes
force_create, shouldn't we create that reflog regardless of
log_all_ref_updates settings?  That is

	if (force_create || should_autocreate_reflog(refname)) {
        	... create it ...

would be more natural to read here, and you would get that for free
if 4/7 checked log_all_ref_updates in should_autocreate_reflog().