Re: git-clone --config order & fetching extra refs during initial clone

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> [Re-sending, as I used an old address for Gábor on the original]
>
> On Sat, Feb 25, 2017 at 07:12:38PM +0000, Robin H. Johnson wrote:
>
>> TL;DR: git-clone ignores any fetch specs passed via --config.
>
> I agree that this is a bug. There's some previous discussion and an RFC
> patch from lat March (author cc'd):
>
>   http://public-inbox.org/git/1457313062-10073-1-git-send-email-szeder@ira.uka.de/
>
> That discussion veered off into alternatives, but I think the v2 posted
> in that thread is taking a sane approach.

Let's see how well it fares by cooking it in 'next' ;-) 

I think it was <1459349623-16443-1-git-send-email-szeder@ira.uka.de>,
which needs a bit of massaging to apply to the current codebase.

-- >8 --
From: SZEDER Gábor <szeder.dev@gmail.com>
Date: Wed, 30 Mar 2016 16:53:43 +0200
Subject: [PATCH] clone: respect configured fetch respecs during initial fetch

Conceptually 'git clone' should behave as if the following commands
were run:

  git init
  git config ... # set default configuration and origin remote
  git fetch
  git checkout   # unless '--bare' is given

However, that initial 'git fetch' behaves differently from any
subsequent fetches, because it takes only the default fetch refspec
into account and ignores all other fetch refspecs that might have
been explicitly specified on the command line (e.g. 'git -c
remote.origin.fetch=<refspec> clone' or 'git clone -c ...').

Check whether there are any fetch refspecs configured for the origin
remote and take all of them into account during the initial fetch as
well.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
---
 builtin/clone.c         | 36 ++++++++++++++++++++++++++++--------
 t/t5611-clone-config.sh | 24 ++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/builtin/clone.c b/builtin/clone.c
index 3f63edbbf9..97229268b6 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -516,7 +516,7 @@ static struct ref *find_remote_branch(const struct ref *refs, const char *branch
 }
 
 static struct ref *wanted_peer_refs(const struct ref *refs,
-		struct refspec *refspec)
+		struct refspec *refspec, unsigned int refspec_count)
 {
 	struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
 	struct ref *local_refs = head;
@@ -537,13 +537,18 @@ static struct ref *wanted_peer_refs(const struct ref *refs,
 			warning(_("Could not find remote branch %s to clone."),
 				option_branch);
 		else {
-			get_fetch_map(remote_head, refspec, &tail, 0);
+			unsigned int i;
+			for (i = 0; i < refspec_count; i++)
+				get_fetch_map(remote_head, &refspec[i], &tail, 0);
 
 			/* if --branch=tag, pull the requested tag explicitly */
 			get_fetch_map(remote_head, tag_refspec, &tail, 0);
 		}
-	} else
-		get_fetch_map(refs, refspec, &tail, 0);
+	} else {
+		unsigned int i;
+		for (i = 0; i < refspec_count; i++)
+			get_fetch_map(refs, &refspec[i], &tail, 0);
+	}
 
 	if (!option_mirror && !option_single_branch)
 		get_fetch_map(refs, tag_refspec, &tail, 0);
@@ -856,7 +861,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	int submodule_progress;
 
 	struct refspec *refspec;
-	const char *fetch_pattern;
+	unsigned int refspec_count = 1;
+	const char **fetch_patterns;
+	const struct string_list *config_fetch_patterns;
 
 	packet_trace_identity("clone");
 	argc = parse_options(argc, argv, prefix, builtin_clone_options,
@@ -1002,9 +1009,21 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (option_required_reference.nr || option_optional_reference.nr)
 		setup_reference();
 
-	fetch_pattern = value.buf;
-	refspec = parse_fetch_refspec(1, &fetch_pattern);
+	strbuf_addf(&key, "remote.%s.fetch", option_origin);
+	config_fetch_patterns = git_config_get_value_multi(key.buf);
+	if (config_fetch_patterns)
+		refspec_count = 1 + config_fetch_patterns->nr;
+	fetch_patterns = xcalloc(refspec_count, sizeof(*fetch_patterns));
+	fetch_patterns[0] = value.buf;
+	if (config_fetch_patterns) {
+		struct string_list_item *fp;
+		unsigned int i = 1;
+		for_each_string_list_item(fp, config_fetch_patterns)
+			fetch_patterns[i++] = fp->string;
+	}
+	refspec = parse_fetch_refspec(refspec_count, fetch_patterns);
 
+	strbuf_reset(&key);
 	strbuf_reset(&value);
 
 	remote = remote_get(option_origin);
@@ -1058,7 +1077,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	refs = transport_get_remote_refs(transport);
 
 	if (refs) {
-		mapped_refs = wanted_peer_refs(refs, refspec);
+		mapped_refs = wanted_peer_refs(refs, refspec, refspec_count);
 		/*
 		 * transport_get_remote_refs() may return refs with null sha-1
 		 * in mapped_refs (see struct transport->get_refs_list
@@ -1147,6 +1166,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	strbuf_release(&value);
 	junk_mode = JUNK_LEAVE_ALL;
 
+	free(fetch_patterns);
 	free(refspec);
 	return err;
 }
diff --git a/t/t5611-clone-config.sh b/t/t5611-clone-config.sh
index e4850b778c..3bed17783b 100755
--- a/t/t5611-clone-config.sh
+++ b/t/t5611-clone-config.sh
@@ -37,6 +37,30 @@ test_expect_success 'clone -c config is available during clone' '
 	test_cmp expect child/file
 '
 
+test_expect_success 'clone -c remote.origin.fetch=<refspec> works' '
+	rm -rf child &&
+	git update-ref refs/grab/it refs/heads/master &&
+	git update-ref refs/keep/out refs/heads/master &&
+	git clone -c "remote.origin.fetch=+refs/grab/*:refs/grab/*" . child &&
+	(
+		cd child &&
+		git for-each-ref --format="%(refname)" refs/grab/ >../actual
+	) &&
+	echo refs/grab/it >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git -c remote.origin.fetch=<refspec> clone works' '
+	rm -rf child &&
+	git -c "remote.origin.fetch=+refs/grab/*:refs/grab/*" clone . child &&
+	(
+		cd child &&
+		git for-each-ref --format="%(refname)" refs/grab/ >../actual
+	) &&
+	echo refs/grab/it >expect &&
+	test_cmp expect actual
+'
+
 # Tests for the hidden file attribute on windows
 is_hidden () {
 	# Use the output of `attrib`, ignore the absolute path