Subject: Re: [PATCH v2 1/2] transport: remove unnecessary indenting in transport_push()

From: Frantisek Hrbata <[email-masked]>
Date: Fri, 20 May 2022 13:53:49 +0200

On Fri, May 20, 2022 at 01:24:28PM +0200, Ævar Arnfjörð Bjarmason wrote:
> 
> On Fri, May 20 2022, Frantisek Hrbata wrote:
> 
> > Remove the big indented block for push_refs() check in transport vtable
> > and let's just return error immediately. Hopefully this makes the code
> > more readable.
> 
> s/push_refs/transport_push/, push_refs is the name of the field in the
> callback (and there's more than just this function).

uf, I will fix that, thank you for noticing.

> 
> This looks good to me....
> 
> > Is there a reason to return 1 instead of -1 when push_refs() is not
> > set in transport vtable? Looking at the code I think it might return
> > -1 also and make it more consistent.
> 
> No, looking at it (I tried renaming the function) the only user is
> builtin/push.c, which we can easily see doesn't care about the 1 v.s. -1 here.
> 
> Perhaps it's worthwhile to add this in-between the two patches you have:
> 	
> 	diff --git a/transport.c b/transport.c
> 	index 0b9c5a427d7..5348fac36ef 100644
> 	--- a/transport.c
> 	+++ b/transport.c
> 	@@ -1283,22 +1283,23 @@ int transport_push(struct repository *r,
> 	 	int quiet = (transport->verbose < 0);
> 	 	int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
> 	 	int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
> 	-	int push_ret, ret, err;
> 	+	int push_ret, err;
> 	+	int ret = -1;
> 	 	struct transport_ls_refs_options transport_options =
> 	 		TRANSPORT_LS_REFS_OPTIONS_INIT;
> 	 
> 	 	*reject_reasons = 0;
> 	 
> 	 	if (transport_color_config() < 0)
> 	-		return -1;
> 	+		goto done;
> 	 
> 	 	if (!transport->vtable->push_refs)
> 	-		return 1;
> 	+		goto done;
> 	 
> 	 	local_refs = get_local_heads();
> 	 
> 	 	if (check_push_refs(local_refs, rs) < 0)
> 	-		return -1;
> 	+		goto done;
> 	 
> 	 	refspec_ref_prefixes(rs, &transport_options.ref_prefixes);
> 	 
> 	@@ -1319,7 +1320,7 @@ int transport_push(struct repository *r,
> 	 		match_flags |= MATCH_REFS_FOLLOW_TAGS;
> 	 
> 	 	if (match_push_refs(local_refs, &remote_refs, rs, match_flags))
> 	-		return -1;
> 	+		goto done;
> 	 
> 	 	if (transport->smart_options &&
> 	 	    transport->smart_options->cas &&
> 	@@ -1333,7 +1334,7 @@ int transport_push(struct repository *r,
> 	 
> 	 	if (!(flags & TRANSPORT_PUSH_NO_HOOK))
> 	 		if (run_pre_push_hook(transport, remote_refs))
> 	-			return -1;
> 	+			goto done;
> 	 
> 	 	if ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
> 	 		      TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
> 	@@ -1417,6 +1418,7 @@ int transport_push(struct repository *r,
> 	 	else if (!quiet && !ret && !transport_refs_pushed(remote_refs))
> 	 		fprintf(stderr, "Everything up-to-date\n");
> 	 
> 	+done:
> 	 	return ret;
> 	 }
> 
> Which would make your new 3/3 truly trivial, i.e. just adding the
> free_refs() for the two.

I was thinking about this too. Just use the done label as a single exit point.
Let me incorporate your suggestions in v3. I will add a 2/3 patch e.g.
"unify return values and exit point for transport_push()"

> 
> *Maybe* (but probably not) it would then make sense to do this as that 3/3:
> 	
> 	diff --git a/transport.c b/transport.c
> 	index 5348fac36ef..d4952bf5f6a 100644
> 	--- a/transport.c
> 	+++ b/transport.c
> 	@@ -1291,15 +1291,17 @@ int transport_push(struct repository *r,
> 	 	*reject_reasons = 0;
> 	 
> 	 	if (transport_color_config() < 0)
> 	-		goto done;
> 	+		return ret;
> 	 
> 	 	if (!transport->vtable->push_refs)
> 	-		goto done;
> 	+		return ret;
> 	 
> 	 	local_refs = get_local_heads();
> 	 
> 	-	if (check_push_refs(local_refs, rs) < 0)
> 	+	if (check_push_refs(local_refs, rs) < 0) {
> 	+		remote_refs = NULL;
> 	 		goto done;
> 	+	}
> 	 
> 	 	refspec_ref_prefixes(rs, &transport_options.ref_prefixes);
> 	 
> 	@@ -1419,6 +1421,8 @@ int transport_push(struct repository *r,
> 	 		fprintf(stderr, "Everything up-to-date\n");
> 	 
> 	 done:
> 	+	free_refs(local_refs);
> 	+	free_refs(remote_refs);
> 	 	return ret;
> 	 }
> 
> I.e. entirely skip the NULL assignment for the two, which helps the
> compiler catch if we don't init it before the later goto's, but because
> of that we'd need to "return" instead of "goto done" for the early ones,
> and set it for the check_push_refs() failure case.
> 
> So nah, probably best just to keep it as you have it, i.e. always "goto
> done".

I agree. Let me prepare v3 and let's see what happens :)

Thank you for your input!

-- 
Frantisek Hrbata