From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 19 Dec 2024 18:58:27 +0000 (-0800)
Subject: Merge branch 'bf/set-head-symref'
X-Git-Tag: v2.48.0-rc1~30
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5f212684abb66c9604e745a2296af8c4bb99961c;p=thirdparty%2Fgit.git

Merge branch 'bf/set-head-symref'

When "git fetch $remote" notices that refs/remotes/$remote/HEAD is
missing and discovers what branch the other side points with its
HEAD, refs/remotes/$remote/HEAD is updated to point to it.

* bf/set-head-symref:
  fetch set_head: handle mirrored bare repositories
  fetch: set remote/HEAD if it does not exist
  refs: add create_only option to refs_update_symref_extended
  refs: add TRANSACTION_CREATE_EXISTS error
  remote set-head: better output for --auto
  remote set-head: refactor for readability
  refs: atomically record overwritten ref in update_symref
  refs: standardize output of refs_read_symbolic_ref
  t/t5505-remote: test failure of set-head
  t/t5505-remote: set default branch to main
---

5f212684abb66c9604e745a2296af8c4bb99961c
diff --cc builtin/remote.c
index 1ad3e70a6b,3dc1135b5c..d5b81445f2
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@@ -1403,12 -1399,40 +1403,41 @@@ static int show(int argc, const char **
  	return result;
  }
  
+ static void report_set_head_auto(const char *remote, const char *head_name,
+ 			struct strbuf *b_local_head, int was_detached) {
+ 	struct strbuf buf_prefix = STRBUF_INIT;
+ 	const char *prev_head = NULL;
+ 
+ 	strbuf_addf(&buf_prefix, "refs/remotes/%s/", remote);
+ 	skip_prefix(b_local_head->buf, buf_prefix.buf, &prev_head);
+ 
+ 	if (prev_head && !strcmp(prev_head, head_name))
+ 		printf(_("'%s/HEAD' is unchanged and points to '%s'\n"),
+ 			remote, head_name);
+ 	else if (prev_head)
+ 		printf(_("'%s/HEAD' has changed from '%s' and now points to '%s'\n"),
+ 			remote, prev_head, head_name);
+ 	else if (!b_local_head->len)
+ 		printf(_("'%s/HEAD' is now created and points to '%s'\n"),
+ 			remote, head_name);
+ 	else if (was_detached && b_local_head->len)
+ 		printf(_("'%s/HEAD' was detached at '%s' and now points to '%s'\n"),
+ 			remote, b_local_head->buf, head_name);
+ 	else
+ 		printf(_("'%s/HEAD' used to point to '%s' "
+ 			"(which is not a remote branch), but now points to '%s'\n"),
+ 			remote, b_local_head->buf, head_name);
+ 	strbuf_release(&buf_prefix);
+ }
+ 
 -static int set_head(int argc, const char **argv, const char *prefix)
 +static int set_head(int argc, const char **argv, const char *prefix,
 +		    struct repository *repo UNUSED)
  {
- 	int i, opt_a = 0, opt_d = 0, result = 0;
- 	struct strbuf buf = STRBUF_INIT, buf2 = STRBUF_INIT;
+ 	int i, opt_a = 0, opt_d = 0, result = 0, was_detached;
+ 	struct strbuf b_head = STRBUF_INIT, b_remote_head = STRBUF_INIT,
+ 		b_local_head = STRBUF_INIT;
  	char *head_name = NULL;
+ 	struct ref_store *refs = get_main_ref_store(the_repository);
  
  	struct option options[] = {
  		OPT_BOOL('a', "auto", &opt_a,
diff --cc refs.c
index 8b71369235,2efa6bcc5c..bc0a60c186
--- a/refs.c
+++ b/refs.c
@@@ -2169,17 -2125,44 +2176,44 @@@ int refs_update_symref_extended(struct 
  {
  	struct ref_transaction *transaction;
  	struct strbuf err = STRBUF_INIT;
- 	int ret = 0;
+ 	int ret = 0, prepret = 0;
  
 -	transaction = ref_store_transaction_begin(refs, &err);
 +	transaction = ref_store_transaction_begin(refs, 0, &err);
- 	if (!transaction ||
- 	    ref_transaction_update(transaction, ref, NULL, NULL,
- 				   target, NULL, REF_NO_DEREF,
- 				   logmsg, &err) ||
- 	    ref_transaction_commit(transaction, &err)) {
+ 	if (!transaction) {
+ 	error_return:
  		ret = error("%s", err.buf);
+ 		goto cleanup;
+ 	}
+ 	if (create_only) {
+ 		if (ref_transaction_create(transaction, ref, NULL, target,
+ 					   REF_NO_DEREF, logmsg, &err))
+ 			goto error_return;
+ 		prepret = ref_transaction_prepare(transaction, &err);
+ 		if (prepret && prepret != TRANSACTION_CREATE_EXISTS)
+ 			goto error_return;
+ 	} else {
+ 		if (ref_transaction_update(transaction, ref, NULL, NULL,
+ 					   target, NULL, REF_NO_DEREF,
+ 					   logmsg, &err) ||
+ 			ref_transaction_prepare(transaction, &err))
+ 			goto error_return;
+ 	}
+ 
+ 	if (referent && refs_read_symbolic_ref(refs, ref, referent) == NOT_A_SYMREF) {
+ 		struct object_id oid;
+ 		if (!refs_read_ref(refs, ref, &oid)) {
+ 			strbuf_addstr(referent, oid_to_hex(&oid));
+ 			ret = NOT_A_SYMREF;
+ 		}
  	}
  
+ 	if (prepret == TRANSACTION_CREATE_EXISTS)
+ 		goto cleanup;
+ 
+ 	if (ref_transaction_commit(transaction, &err))
+ 		goto error_return;
+ 
+ cleanup:
  	strbuf_release(&err);
  	if (transaction)
  		ref_transaction_free(transaction);
diff --cc refs/reftable-backend.c
index 31c58db29f,d764c2c3af..8a2a5b847c
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@@ -919,9 -829,15 +919,13 @@@ static int reftable_be_read_symbolic_re
  	if (ret)
  		return ret;
  
 -	ret = reftable_stack_read_ref(stack, refname, &ref);
 +	ret = reftable_backend_read_ref(be, refname, &oid, referent, &type);
- 	if (type != REF_ISSYMREF)
+ 	if (ret)
  		ret = -1;
 -	else if (ref.value_type == REFTABLE_REF_SYMREF)
 -		strbuf_addstr(referent, ref.value.symref);
++	else if (type == REF_ISSYMREF)
++		; /* happy */
+ 	else
+ 		ret = NOT_A_SYMREF;
 -
 -	reftable_ref_record_release(&ref);
  	return ret;
  }
  
diff --cc t/t5505-remote.sh
index 08424e878e,2600add82a..7411aa770d
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@@ -2,6 -2,10 +2,9 @@@
  
  test_description='git remote porcelain-ish'
  
+ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+ 
 -TEST_PASSES_SANITIZE_LEAK=true
  . ./test-lib.sh
  
  setup_repository () {