Subject: Re: [PATCH v2] RFC: tracking branches: add advice to ambiguous refspec error

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Tue, 22 Mar 2022 11:04:32 +0100

On Tue, Mar 22 2022, Tao Klerks via GitGitGadget wrote:

> From: Tao Klerks <[email-masked]>
> [...]
Looking much better!

> diff --git a/Documentation/config/advice.txt b/Documentation/config/advice.txt
> index 063eec2511d..abfac4f664b 100644
> --- a/Documentation/config/advice.txt
> +++ b/Documentation/config/advice.txt
> @@ -126,4 +126,8 @@ advice.*::
>  		Advice shown when either linkgit:git-add[1] or linkgit:git-rm[1]
>  		is asked to update index entries outside the current sparse
>  		checkout.
> +	ambiguousFetchRefspec::
> +		Advice shown when branch tracking relationship setup fails due
> +		to multiple remotes' refspecs mapping to the same remote
> +		tracking namespace in the repo.

Let's add this in alphabetical section order. It's *somewhat* true of
the order now, but for some, but in any case I've got a WIP patch to
sort these, so since it's new adding it at the top would save us the
churn :)

> +struct find_tracked_branch_cb {
> +	struct tracking *tracking;
> +	struct strbuf remotes_advice;
> +};

Nice, thanks!

>  static int find_tracked_branch(struct remote *remote, void *priv)
>  {
> -	struct tracking *tracking = priv;
> +	struct find_tracked_branch_cb *ftb = priv;
> +	struct tracking *tracking = ftb->tracking;
>  
>  	if (!remote_find_tracking(remote, &tracking->spec)) {
>  		if (++tracking->matches == 1) {
> @@ -28,6 +34,7 @@ static int find_tracked_branch(struct remote *remote, void *priv)
>  			free(tracking->spec.src);
>  			string_list_clear(tracking->srcs, 0);
>  		}
> +		strbuf_addf(&ftb->remotes_advice, "  %s\n", remote->name);

Do this as:

    strbuf_addf([...], _("  %s\n"), [...]);

And add a TRANSLATORS comment similar to show_ambiguous_object() in
object-name.c. I.e. the alignment needs to be translatable for RTL
languages.

> +static const char ambiguous_refspec_advice_pre[] =
> +N_("\n"
> +"There are multiple remotes whose fetch refspecs map to the remote\n"
> +"tracking ref";)
> +static const char ambiguous_refspec_advice_post[] =
> +N_("This is typically a configuration error.\n"
> +"\n"
> +"To support setting up tracking branches, ensure that\n"
> +"different remotes' fetch refspecs map into different\n"
> +"tracking namespaces.\n");

These were split up before since we incrementally built the message....

Also, is the \n at the beginning/end really needed?

>  /*
>   * This is called when new_ref is branched off of orig_ref, and tries
>   * to infer the settings for branch.<new_ref>.{remote,merge} from the
> @@ -228,12 +247,16 @@ static void setup_tracking(const char *new_ref, const char *orig_ref,
>  	struct tracking tracking;
>  	struct string_list tracking_srcs = STRING_LIST_INIT_DUP;
>  	int config_flags = quiet ? 0 : BRANCH_CONFIG_VERBOSE;
> +	struct find_tracked_branch_cb ftb_cb = {
> +		.tracking = &tracking,
> +		.remotes_advice = STRBUF_INIT,
> +	};
>  
>  	memset(&tracking, 0, sizeof(tracking));
>  	tracking.spec.dst = (char *)orig_ref;
>  	tracking.srcs = &tracking_srcs;
>  	if (track != BRANCH_TRACK_INHERIT)
> -		for_each_remote(find_tracked_branch, &tracking);
> +		for_each_remote(find_tracked_branch, &ftb_cb);
>  	else if (inherit_tracking(&tracking, orig_ref))
>  		return;
>  
> @@ -248,9 +271,18 @@ static void setup_tracking(const char *new_ref, const char *orig_ref,
>  			return;
>  		}
>  
> -	if (tracking.matches > 1)
> -		die(_("not tracking: ambiguous information for ref %s"),
> -		    orig_ref);
> +	if (tracking.matches > 1) {
> +		int status = die_message(_("not tracking: ambiguous information for ref %s"),
> +					    orig_ref);
> +		if (advice_enabled(ADVICE_AMBIGUOUS_FETCH_REFSPEC))
> +			advise("%s %s:\n%s\n%s",
> +			       _(ambiguous_refspec_advice_pre),
> +			       orig_ref,
> +			       ftb_cb.remotes_advice.buf,
> +			       _(ambiguous_refspec_advice_post)
> +			       );

...but now we don't, so this should just be inlined here. I.e. made it
one big translatable _() message, the only parameters need to be the
orig_ref and the "remote_advice" buf.

We're also missing a strbuf_release() here. You can just add it to the
"cleanup" omitted from the context:

	strbuf_release(&ftb_cb.remotes_advice);