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[PATCH v3 3/3] clone: respect remote unborn HEAD

From
JTJonathan Tan <jonathantanmy@google.com>
Date
Dec 21, 2020, 22:31 UTC
Message-ID
<c2303dc9761493decd7a21a7f1e89d6dd9c646e4.1608587839.git.jonathantanmy@google.com>
In-Reply-To
<cover.1608587839.git.jonathantanmy@google.com>

Teach Git to use the "unborn" feature introduced in a previous patch as follows: Git will always send the "unborn" argument if it is supported by the server. During "git clone", if cloning an empty repository, Git will use the new information to determine the local branch to create. In all other cases, Git will ignore it.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 Documentation/config/init.txt |  2 +-
 builtin/clone.c               | 19 ++++++++++++++++---
 connect.c                     | 28 ++++++++++++++++++++++++----
 t/t5606-clone-options.sh      |  7 ++++---
 t/t5702-protocol-v2.sh        |  9 +++++++++
 5 files changed, 54 insertions(+), 11 deletions(-)
diff --git a/Documentation/config/init.txt b/Documentation/config/init.txt
index dc77f8c844..79c79d6617 100644
--- a/Documentation/config/init.txt
+++ b/Documentation/config/init.txt
@@ -4,4 +4,4 @@ init.templateDir::
 
 init.defaultBranch::
 	Allows overriding the default branch name e.g. when initializing
-	a new repository or when cloning an empty repository.
+	a new repository.
diff --git a/builtin/clone.c b/builtin/clone.c
index 70f9450db4..217c87fddf 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -980,6 +980,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	int submodule_progress;
 
 	struct strvec ref_prefixes = STRVEC_INIT;
+	char *unborn_head_target = NULL;
 
 	packet_trace_identity("clone");
 
@@ -1264,7 +1265,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (!option_no_tags)
 		strvec_push(&ref_prefixes, "refs/tags/");
 
-	refs = transport_get_remote_refs(transport, &ref_prefixes, NULL);
+	refs = transport_get_remote_refs(transport, &ref_prefixes,
+					 &unborn_head_target);
 
 	if (refs) {
 		int hash_algo = hash_algo_by_ptr(transport_get_hash_algo(transport));
@@ -1323,10 +1325,20 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		remote_head = NULL;
 		option_no_checkout = 1;
 		if (!option_bare) {
-			const char *branch = git_default_branch_name();
-			char *ref = xstrfmt("refs/heads/%s", branch);
+			const char *branch;
+			char *ref;
+
+			if (unborn_head_target &&
+			    skip_prefix(unborn_head_target, "refs/heads/", &branch)) {
+				ref = unborn_head_target;
+				unborn_head_target = NULL;
+			} else {
+				branch = git_default_branch_name();
+				ref = xstrfmt("refs/heads/%s", branch);
+			}
 
 			install_branch_config(0, branch, remote_name, ref);
+			create_symref("HEAD", ref, "");
 			free(ref);
 		}
 	}
@@ -1373,6 +1385,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	strbuf_release(&key);
 	junk_mode = JUNK_LEAVE_ALL;
 
+	free(unborn_head_target);
 	strvec_clear(&ref_prefixes);
 	return err;
 }
diff --git a/connect.c b/connect.c
index 99d9052365..3c35324b4c 100644
--- a/connect.c
+++ b/connect.c
@@ -376,7 +376,8 @@ struct ref **get_remote_heads(struct packet_reader *reader,
 }
 
 /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
-static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
+static int process_ref_v2(struct packet_reader *reader, struct ref ***list,
+			  char **unborn_head_target)
 {
 	int ret = 1;
 	int i = 0;
@@ -397,6 +398,25 @@ static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
 		goto out;
 	}
 
+	if (!strcmp("unborn", line_sections.items[i].string)) {
+		i++;
+		if (unborn_head_target &&
+		    !strcmp("HEAD", line_sections.items[i++].string)) {
+			/*
+			 * Look for the symref target (if any). If found,
+			 * return it to the caller.
+			 */
+			for (; i < line_sections.nr; i++) {
+				const char *arg = line_sections.items[i].string;
+
+				if (skip_prefix(arg, "symref-target:", &arg)) {
+					*unborn_head_target = xstrdup(arg);
+					break;
+				}
+			}
+		}
+		goto out;
+	}
 	if (parse_oid_hex_algop(line_sections.items[i++].string, &old_oid, &end, reader->hash_algo) ||
 	    *end) {
 		ret = 0;
@@ -489,6 +509,8 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 	if (!for_push)
 		packet_write_fmt(fd_out, "peel\n");
 	packet_write_fmt(fd_out, "symrefs\n");
+	if (server_supports_feature("ls-refs", "unborn", 0))
+		packet_write_fmt(fd_out, "unborn\n");
 	for (i = 0; ref_prefixes && i < ref_prefixes->nr; i++) {
 		packet_write_fmt(fd_out, "ref-prefix %s\n",
 				 ref_prefixes->v[i]);
@@ -497,9 +519,7 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 
 	/* Process response from server */
 	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
-		if (unborn_head_target)
-			BUG("NEEDSWORK: provide unborn HEAD target to caller while reading refs");
-		if (!process_ref_v2(reader, &list))
+		if (!process_ref_v2(reader, &list, unborn_head_target))
 			die(_("invalid ls-refs response: %s"), reader->line);
 	}
 
diff --git a/t/t5606-clone-options.sh b/t/t5606-clone-options.sh
index 7f082fb23b..67a4c6d05b 100755
--- a/t/t5606-clone-options.sh
+++ b/t/t5606-clone-options.sh
@@ -102,11 +102,12 @@ test_expect_success 'redirected clone -v does show progress' '
 '
 
 test_expect_success 'chooses correct default initial branch name' '
-	git init --bare empty &&
+	git -c init.defaultBranch=foo init --bare empty &&
+	test_config -C empty lsrefs.allowUnborn true &&
 	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME= \
 	git -c init.defaultBranch=up clone empty whats-up &&
-	test refs/heads/up = $(git -C whats-up symbolic-ref HEAD) &&
-	test refs/heads/up = $(git -C whats-up config branch.up.merge)
+	test refs/heads/foo = $(git -C whats-up symbolic-ref HEAD) &&
+	test refs/heads/foo = $(git -C whats-up config branch.foo.merge)
 '
 
 test_expect_success 'guesses initial branch name correctly' '
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 7d5b17909b..4fbbe5aff5 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -209,6 +209,15 @@ test_expect_success 'clone with file:// using protocol v2' '
 	grep "ref-prefix refs/tags/" log
 '
 
+test_expect_success 'clone of empty repo propagates name of default branch' '
+	git -c init.defaultBranch=mydefaultbranch init file_empty_parent &&
+	test_config -C file_empty_parent lsrefs.allowUnborn true &&
+
+	git -c init.defaultBranch=main -c protocol.version=2 \
+		clone "file://$(pwd)/file_empty_parent" file_empty_child &&
+	grep "refs/heads/mydefaultbranch" file_empty_child/.git/HEAD
+'
+
 test_expect_success 'fetch with file:// using protocol v2' '
 	test_when_finished "rm -f log" &&
 
-- 
2.29.2.729.g45daf8777d-goog
Previous: Jonathan TanNext: Junio C Hamano
Message 42 of 109 in “Cloning empty repository uses locally configured default branch name”
  1. Jonathan TanDec 8, 2020
  2. Junio C HamanoDec 8, 2020
  3. brian m. carlsonDec 8, 2020
  4. Jonathan TanDec 8, 2020
  5. Junio C HamanoDec 8, 2020
  6. Jeff KingDec 8, 2020
  7. Jonathan TanDec 8, 2020
  8. Jeff KingDec 8, 2020
  9. clone: in protocol v2, use remote's default branchJonathan Tan, Dec 11, 2020
  10. Junio C HamanoDec 11, 2020
  11. Ævar Arnfjörð BjarmasonDec 14, 2020
  12. Felipe ContrerasDec 14, 2020
  13. Junio C HamanoDec 14, 2020
  14. Ævar Arnfjörð BjarmasonDec 15, 2020
  15. Junio C HamanoDec 15, 2020
  16. Jeff KingDec 15, 2020
  17. Junio C HamanoDec 15, 2020
  18. Jeff KingDec 15, 2020
  19. Junio C HamanoDec 16, 2020
  20. Jeff KingDec 16, 2020
  21. Junio C HamanoDec 16, 2020
  22. Jeff KingDec 18, 2020
  23. Felipe ContrerasDec 15, 2020
  24. Jonathan TanDec 14, 2020
  25. Felipe ContrerasDec 14, 2020
  26. Jeff KingDec 15, 2020
  27. Jonathan TanDec 15, 2020
  28. 0/3 Cloning with remote unborn HEADJonathan Tan, Dec 16, 2020
  29. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Dec 16, 2020
  30. Junio C HamanoDec 16, 2020
  31. Jonathan TanDec 16, 2020
  32. Jeff KingDec 16, 2020
  33. Jonathan TanDec 16, 2020
  34. Junio C HamanoDec 17, 2020
  35. Jeff KingDec 18, 2020
  36. 2/3 connect, transport: add no-op arg for future patchJonathan Tan, Dec 16, 2020
  37. Junio C HamanoDec 16, 2020
  38. 3/3 clone: respect remote unborn HEADJonathan Tan, Dec 16, 2020
  39. 0/3 Cloning with remote unborn HEADJonathan Tan, Dec 21, 2020
  40. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Dec 21, 2020
  41. 2/3 connect, transport: add no-op arg for future patchJonathan Tan, Dec 21, 2020
  42. 3/3 clone: respect remote unborn HEADJonathan Tan, Dec 21, 2020
  43. Junio C HamanoDec 21, 2020
  44. Jeff KingJan 21, 2021
  45. 0/3 Cloning with remote unborn HEADJonathan Tan, Dec 22, 2020
  46. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Dec 22, 2020
  47. Jeff KingJan 21, 2021
  48. Jonathan TanJan 26, 2021
  49. Jeff KingJan 26, 2021
  50. 2/3 connect, transport: add no-op arg for future patchJonathan Tan, Dec 22, 2020
  51. Jeff KingJan 21, 2021
  52. Jonathan TanJan 26, 2021
  53. 3/3 clone: respect remote unborn HEADJonathan Tan, Dec 22, 2020
  54. Jeff KingJan 21, 2021
  55. Jonathan TanJan 26, 2021
  56. Jeff KingJan 26, 2021
  57. Junio C HamanoJan 28, 2021
  58. Junio C HamanoDec 22, 2020
  59. 0/3 Cloning with remote unborn HEADJonathan Tan, Jan 26, 2021
  60. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Jan 26, 2021
  61. Junio C HamanoJan 26, 2021
  62. Jeff KingJan 26, 2021
  63. Junio C HamanoJan 26, 2021
  64. Junio C HamanoJan 26, 2021
  65. Jonathan TanJan 30, 2021
  66. Jonathan TanJan 29, 2021
  67. Junio C HamanoJan 29, 2021
  68. Jonathan TanFeb 2, 2021
  69. Junio C HamanoFeb 2, 2021
  70. Ævar Arnfjörð BjarmasonJan 27, 2021
  71. Jonathan TanJan 30, 2021
  72. 2/3 connect, transport: encapsulate arg in structJonathan Tan, Jan 26, 2021
  73. Junio C HamanoJan 26, 2021
  74. Jonathan TanJan 30, 2021
  75. 3/3 clone: respect remote unborn HEADJonathan Tan, Jan 26, 2021
  76. Junio C HamanoJan 26, 2021
  77. Jonathan TanJan 30, 2021
  78. Ævar Arnfjörð BjarmasonJan 27, 2021
  79. Jonathan TanJan 30, 2021
  80. Ævar Arnfjörð BjarmasonJan 30, 2021
  81. Jonathan TanFeb 2, 2021
  82. Ævar Arnfjörð BjarmasonFeb 3, 2021
  83. Junio C HamanoFeb 5, 2021
  84. Junio C HamanoJan 27, 2021
  85. Jeff KingJan 27, 2021
  86. Junio C HamanoJan 27, 2021
  87. 0/3 Cloning with remote unborn HEADJonathan Tan, Feb 2, 2021
  88. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Feb 2, 2021
  89. Junio C HamanoFeb 2, 2021
  90. Jonathan TanFeb 2, 2021
  91. Junio C HamanoFeb 2, 2021
  92. Jonathan TanFeb 3, 2021
  93. 2/3 connect, transport: encapsulate arg in structJonathan Tan, Feb 2, 2021
  94. 3/3 clone: respect remote unborn HEADJonathan Tan, Feb 2, 2021
  95. 0/3 Cloning with remote unborn HEADJonathan Tan, Feb 5, 2021
  96. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Feb 5, 2021
  97. Jeff KingFeb 5, 2021
  98. 2/3 connect, transport: encapsulate arg in structJonathan Tan, Feb 5, 2021
  99. 3/3 clone: respect remote unborn HEADJonathan Tan, Feb 5, 2021
  100. Junio C HamanoFeb 5, 2021
  101. Ævar Arnfjörð BjarmasonFeb 5, 2021
  102. Junio C HamanoFeb 5, 2021
  103. Jeff KingFeb 5, 2021
  104. 0/3 Cloning with remote unborn HEADJonathan Tan, Feb 5, 2021
  105. 3/3 clone: respect remote unborn HEADJonathan Tan, Feb 5, 2021
  106. 2/3 connect, transport: encapsulate arg in structJonathan Tan, Feb 5, 2021
  107. 1/3 ls-refs: report unborn targets of symrefsJonathan Tan, Feb 5, 2021
  108. Junio C HamanoFeb 6, 2021
  109. Junio C HamanoFeb 8, 2021

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