git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v6 8/8] update-ref: add --batch-updates flag for stdin mode

From
Karthik Nayak <karthik.188@gmail.com>
Date
Apr 8, 2025, 08:51 UTC
Message-ID
<20250408085120.614893-9-karthik.188@gmail.com>
In-Reply-To
<20250408085120.614893-1-karthik.188@gmail.com>

When updating multiple references through stdin, Git's update-ref command normally aborts the entire transaction if any single update fails. This atomic behavior prevents partial updates. Introduce a new batch update system, where the updates the performed together similar but individual updates are allowed to fail.

Add a new `--batch-updates` flag that allows the transaction to continue even when individual reference updates fail. This flag can only be used in `--stdin` mode and builds upon the batch update support added to the refs subsystem in the previous commits. When enabled, failed updates are reported in the following format:

  rejected SP (<old-oid> | <old-target>) SP (<new-oid> | <new-target>) SP <rejection-reason> LF

Update the documentation to reflect this change and also tests to cover different scenarios where an update could be rejected.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
 Documentation/git-update-ref.adoc |  14 +-
 builtin/update-ref.c              |  66 ++++++++-
 t/t1400-update-ref.sh             | 233 ++++++++++++++++++++++++++++++
 3 files changed, 306 insertions(+), 7 deletions(-)
diff --git a/Documentation/git-update-ref.adoc b/Documentation/git-update-ref.adoc
index 9e6935d38d..9310ce9768 100644
--- a/Documentation/git-update-ref.adoc
+++ b/Documentation/git-update-ref.adoc
@@ -7,8 +7,10 @@ git-update-ref - Update the object name stored in a ref safely
 
 SYNOPSIS
 --------
-[verse]
-'git update-ref' [-m <reason>] [--no-deref] (-d <ref> [<old-oid>] | [--create-reflog] <ref> <new-oid> [<old-oid>] | --stdin [-z])
+[synopsis]
+git update-ref [-m <reason>] [--no-deref] -d <ref> [<old-oid>]
+git update-ref [-m <reason>] [--no-deref] [--create-reflog] <ref> <new-oid> [<old-oid>]
+git update-ref [-m <reason>] [--no-deref] --stdin [-z] [--batch-updates]
 
 DESCRIPTION
 -----------
@@ -57,6 +59,14 @@ performs all modifications together.  Specify commands of the form:
 With `--create-reflog`, update-ref will create a reflog for each ref
 even if one would not ordinarily be created.
 
+With `--batch-updates`, update-ref executes the updates in a batch but allows
+individual updates to fail due to invalid or incorrect user input, applying only
+the successful updates. However, system-related errors—such as I/O failures or
+memory issues—will result in a full failure of all batched updates. Any failed
+updates will be reported in the following format:
+
+	rejected SP (<old-oid> | <old-target>) SP (<new-oid> | <new-target>) SP <rejection-reason> LF
+
 Quote fields containing whitespace as if they were strings in C source
 code; i.e., surrounded by double-quotes and with backslash escapes.
 Use 40 "0" characters or the empty string to specify a zero value.  To
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 1d541e13ad..111d6473ad 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -5,6 +5,7 @@
 #include "config.h"
 #include "gettext.h"
 #include "hash.h"
+#include "hex.h"
 #include "refs.h"
 #include "object-name.h"
 #include "parse-options.h"
@@ -13,7 +14,7 @@
 static const char * const git_update_ref_usage[] = {
 	N_("git update-ref [<options>] -d <refname> [<old-oid>]"),
 	N_("git update-ref [<options>]    <refname> <new-oid> [<old-oid>]"),
-	N_("git update-ref [<options>] --stdin [-z]"),
+	N_("git update-ref [<options>] --stdin [-z] [--batch-updates]"),
 	NULL
 };
 
@@ -565,6 +566,49 @@ static void parse_cmd_abort(struct ref_transaction *transaction,
 	report_ok("abort");
 }
 
+static void print_rejected_refs(const char *refname,
+				const struct object_id *old_oid,
+				const struct object_id *new_oid,
+				const char *old_target,
+				const char *new_target,
+				enum ref_transaction_error err,
+				void *cb_data UNUSED)
+{
+	struct strbuf sb = STRBUF_INIT;
+	const char *reason = "";
+
+	switch (err) {
+	case REF_TRANSACTION_ERROR_NAME_CONFLICT:
+		reason = "refname conflict";
+		break;
+	case REF_TRANSACTION_ERROR_CREATE_EXISTS:
+		reason = "reference already exists";
+		break;
+	case REF_TRANSACTION_ERROR_NONEXISTENT_REF:
+		reason = "reference does not exist";
+		break;
+	case REF_TRANSACTION_ERROR_INCORRECT_OLD_VALUE:
+		reason = "incorrect old value provided";
+		break;
+	case REF_TRANSACTION_ERROR_INVALID_NEW_VALUE:
+		reason = "invalid new value provided";
+		break;
+	case REF_TRANSACTION_ERROR_EXPECTED_SYMREF:
+		reason = "expected symref but found regular ref";
+		break;
+	default:
+		reason = "unkown failure";
+	}
+
+	strbuf_addf(&sb, "rejected %s %s %s %s\n", refname,
+		    new_oid ? oid_to_hex(new_oid) : new_target,
+		    old_oid ? oid_to_hex(old_oid) : old_target,
+		    reason);
+
+	fwrite(sb.buf, sb.len, 1, stdout);
+	strbuf_release(&sb);
+}
+
 static void parse_cmd_commit(struct ref_transaction *transaction,
 			     const char *next, const char *end UNUSED)
 {
@@ -573,6 +617,10 @@ static void parse_cmd_commit(struct ref_transaction *transaction,
 		die("commit: extra input: %s", next);
 	if (ref_transaction_commit(transaction, &error))
 		die("commit: %s", error.buf);
+
+	ref_transaction_for_each_rejected_update(transaction,
+						 print_rejected_refs, NULL);
+
 	report_ok("commit");
 	ref_transaction_free(transaction);
 }
@@ -609,7 +657,7 @@ static const struct parse_cmd {
 	{ "commit",        parse_cmd_commit,        0, UPDATE_REFS_CLOSED },
 };
 
-static void update_refs_stdin(void)
+static void update_refs_stdin(unsigned int flags)
 {
 	struct strbuf input = STRBUF_INIT, err = STRBUF_INIT;
 	enum update_refs_state state = UPDATE_REFS_OPEN;
@@ -617,7 +665,7 @@ static void update_refs_stdin(void)
 	int i, j;
 
 	transaction = ref_store_transaction_begin(get_main_ref_store(the_repository),
-						  0, &err);
+						  flags, &err);
 	if (!transaction)
 		die("%s", err.buf);
 
@@ -685,7 +733,7 @@ static void update_refs_stdin(void)
 			 */
 			state = cmd->state;
 			transaction = ref_store_transaction_begin(get_main_ref_store(the_repository),
-								  0, &err);
+								  flags, &err);
 			if (!transaction)
 				die("%s", err.buf);
 
@@ -701,6 +749,8 @@ static void update_refs_stdin(void)
 		/* Commit by default if no transaction was requested. */
 		if (ref_transaction_commit(transaction, &err))
 			die("%s", err.buf);
+		ref_transaction_for_each_rejected_update(transaction,
+						 print_rejected_refs, NULL);
 		ref_transaction_free(transaction);
 		break;
 	case UPDATE_REFS_STARTED:
@@ -727,6 +777,8 @@ int cmd_update_ref(int argc,
 	struct object_id oid, oldoid;
 	int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0;
 	int create_reflog = 0;
+	unsigned int flags = 0;
+
 	struct option options[] = {
 		OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
 		OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
@@ -735,6 +787,8 @@ int cmd_update_ref(int argc,
 		OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
 		OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
 		OPT_BOOL( 0 , "create-reflog", &create_reflog, N_("create a reflog")),
+		OPT_BIT('0', "batch-updates", &flags, N_("batch reference updates"),
+			REF_TRANSACTION_ALLOW_FAILURE),
 		OPT_END(),
 	};
 
@@ -756,8 +810,10 @@ int cmd_update_ref(int argc,
 			usage_with_options(git_update_ref_usage, options);
 		if (end_null)
 			line_termination = '\0';
-		update_refs_stdin();
+		update_refs_stdin(flags);
 		return 0;
+	} else if (flags & REF_TRANSACTION_ALLOW_FAILURE) {
+		die("--batch-updates can only be used with --stdin");
 	}
 
 	if (end_null)
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 29045aad43..d29d23cb89 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -2066,6 +2066,239 @@ do
 		grep "$(git rev-parse $a) $(git rev-parse $a)" actual
 	'
 
+	test_expect_success "stdin $type batch-updates" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit commit &&
+			head=$(git rev-parse HEAD) &&
+
+			format_command $type "update refs/heads/ref1" "$head" "$Z" >stdin &&
+			format_command $type "update refs/heads/ref2" "$head" "$Z" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin &&
+			echo $head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			git rev-parse refs/heads/ref2 >actual &&
+			test_cmp expect actual
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with invalid new_oid" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref1 $head &&
+			git update-ref refs/heads/ref2 $head &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref2" "$(test_oid 001)" "$head" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			echo $head >expect &&
+			git rev-parse refs/heads/ref2 >actual &&
+			test_cmp expect actual &&
+			test_grep -q "invalid new value provided" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with non-commit new_oid" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			head_tree=$(git rev-parse HEAD^{tree}) &&
+			git update-ref refs/heads/ref1 $head &&
+			git update-ref refs/heads/ref2 $head &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref2" "$head_tree" "$head" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			echo $head >expect &&
+			git rev-parse refs/heads/ref2 >actual &&
+			test_cmp expect actual &&
+			test_grep -q "invalid new value provided" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with non-existent ref" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref1 $head &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref2" "$old_head" "$head" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			test_must_fail git rev-parse refs/heads/ref2 &&
+			test_grep -q "reference does not exist" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with dangling symref" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref1 $head &&
+			git symbolic-ref refs/heads/ref2 refs/heads/nonexistent &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref2" "$old_head" "$head" >>stdin &&
+			git update-ref $type --no-deref --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			echo $head >expect &&
+			test_must_fail git rev-parse refs/heads/ref2 &&
+			test_grep -q "reference does not exist" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with regular ref as symref" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref1 $head &&
+			git update-ref refs/heads/ref2 $head &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "symref-update refs/heads/ref2" "$old_head" "ref" "refs/heads/nonexistent" >>stdin &&
+			git update-ref $type --no-deref --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			echo $head >expect &&
+			echo $head >expect &&
+			git rev-parse refs/heads/ref2 >actual &&
+			test_cmp expect actual &&
+			test_grep -q "expected symref but found regular ref" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with invalid old_oid" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref1 $head &&
+			git update-ref refs/heads/ref2 $head &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref2" "$old_head" "$Z" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			echo $head >expect &&
+			git rev-parse refs/heads/ref2 >actual &&
+			test_cmp expect actual &&
+			test_grep -q "reference already exists" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates with incorrect old oid" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref1 $head &&
+			git update-ref refs/heads/ref2 $head &&
+
+			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref2" "$head" "$old_head" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref1 >actual &&
+			test_cmp expect actual &&
+			echo $head >expect &&
+			git rev-parse refs/heads/ref2 >actual &&
+			test_cmp expect actual &&
+			test_grep -q "incorrect old value provided" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates refname conflict" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref/foo $head &&
+
+			format_command $type "update refs/heads/ref/foo" "$old_head" "$head" >stdin &&
+			format_command $type "update refs/heads/ref" "$old_head" "" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/ref/foo >actual &&
+			test_cmp expect actual &&
+			test_grep -q "refname conflict" stdout
+		)
+	'
+
+	test_expect_success "stdin $type batch-updates refname conflict new ref" '
+		git init repo &&
+		test_when_finished "rm -fr repo" &&
+		(
+			cd repo &&
+			test_commit one &&
+			old_head=$(git rev-parse HEAD) &&
+			test_commit two &&
+			head=$(git rev-parse HEAD) &&
+			git update-ref refs/heads/ref/foo $head &&
+
+			format_command $type "update refs/heads/foo" "$old_head" "" >stdin &&
+			format_command $type "update refs/heads/ref" "$old_head" "" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			echo $old_head >expect &&
+			git rev-parse refs/heads/foo >actual &&
+			test_cmp expect actual &&
+			test_grep -q "refname conflict" stdout
+		)
+	'
 done
 
 test_expect_success 'update-ref should also create reflog for HEAD' '

-- 
2.48.1
Previous: Karthik NayakNext: Junio C Hamano
Message 45 of 49 in “refs: introduce support for partial reference transactions”
  1. 0/6 refs: introduce support for partial reference transactionsKarthik Nayak, Feb 7, 2025
  2. 1/6 refs/files: remove duplicate check in `split_symref_update()`Karthik Nayak, Feb 7, 2025
  3. Patrick SteinhardtFeb 7, 2025
  4. Karthik NayakFeb 11, 2025
  5. 2/6 refs: move duplicate refname update check to generic layerKarthik Nayak, Feb 7, 2025
  6. Patrick SteinhardtFeb 7, 2025
  7. Karthik NayakFeb 11, 2025
  8. 3/6 refs/files: remove duplicate duplicates checkKarthik Nayak, Feb 7, 2025
  9. Patrick SteinhardtFeb 7, 2025
  10. 4/6 refs/reftable: extract code from the transaction preparationKarthik Nayak, Feb 7, 2025
  11. 5/6 refs: implement partial reference transaction supportKarthik Nayak, Feb 7, 2025
  12. Patrick SteinhardtFeb 7, 2025
  13. Karthik NayakFeb 21, 2025
  14. 6/6 update-ref: add --allow-partial flag for stdin modeKarthik Nayak, Feb 7, 2025
  15. Patrick SteinhardtFeb 7, 2025
  16. Karthik NayakFeb 21, 2025
  17. Phillip WoodFeb 11, 2025
  18. Phillip WoodFeb 11, 2025
  19. Karthik NayakFeb 12, 2025
  20. Karthik NayakFeb 12, 2025
  21. Phillip WoodFeb 19, 2025
  22. Patrick SteinhardtFeb 19, 2025
  23. Karthik NayakFeb 21, 2025
  24. 0/8 refs: introduce support for batched reference updatesKarthik Nayak, Mar 27, 2025
  25. 1/8 refs/files: remove redundant check in split_symref_update()Karthik Nayak, Mar 27, 2025
  26. 2/8 refs: move duplicate refname update check to generic layerKarthik Nayak, Mar 27, 2025
  27. 3/8 refs/files: remove duplicate duplicates checkKarthik Nayak, Mar 27, 2025
  28. 4/8 refs/reftable: extract code from the transaction preparationKarthik Nayak, Mar 27, 2025
  29. 5/8 refs: introduce enum-based transaction error typesKarthik Nayak, Mar 27, 2025
  30. 6/8 refs: implement batch reference update supportKarthik Nayak, Mar 27, 2025
  31. 7/8 refs: support rejection in batch updates during F/D checksKarthik Nayak, Mar 27, 2025
  32. 8/8 update-ref: add --batch-updates flag for stdin modeKarthik Nayak, Mar 27, 2025
  33. Jean-Noël AVILAMar 28, 2025
  34. Junio C HamanoMar 29, 2025
  35. Karthik NayakMar 29, 2025
  36. Patrick SteinhardtMar 28, 2025
  37. 0/8 refs: introduce support for batched reference updatesKarthik Nayak, Apr 8, 2025
  38. 1/8 refs/files: remove redundant check in split_symref_update()Karthik Nayak, Apr 8, 2025
  39. 2/8 refs: move duplicate refname update check to generic layerKarthik Nayak, Apr 8, 2025
  40. 3/8 refs/files: remove duplicate duplicates checkKarthik Nayak, Apr 8, 2025
  41. 4/8 refs/reftable: extract code from the transaction preparationKarthik Nayak, Apr 8, 2025
  42. 5/8 refs: introduce enum-based transaction error typesKarthik Nayak, Apr 8, 2025
  43. 6/8 refs: implement batch reference update supportKarthik Nayak, Apr 8, 2025
  44. 7/8 refs: support rejection in batch updates during F/D checksKarthik Nayak, Apr 8, 2025
  45. 8/8 update-ref: add --batch-updates flag for stdin modeKarthik Nayak, Apr 8, 2025
  46. Junio C HamanoApr 8, 2025
  47. Karthik NayakApr 8, 2025
  48. Junio C HamanoApr 8, 2025
  49. Karthik NayakApr 10, 2025

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.