From 2343720967aac3725148e1a6690dbe6c98fe5f2e Mon Sep 17 00:00:00 2001 From: Karthik Nayak Date: Fri, 7 Jun 2024 15:33:01 +0200 Subject: [PATCH] update-ref: add support for 'symref-delete' command Add a new command 'symref-delete' to allow deletions of symbolic refs in a transaction via the '--stdin' mode of the 'git-update-ref' command. The 'symref-delete' command can, when given an , delete the provided only when it points to . This command is only compatible with the 'no-deref' mode because we optionally want to check the 'old_target' of the ref being deleted. De-referencing a symbolic ref would provide a regular ref and we already have the 'delete' command for regular refs. While users can also use 'git symbolic-ref -d' to delete symbolic refs, the 'symref-delete' command in 'git-update-ref' allows users to do so within a transaction, which promises atomicity of the operation and can be batched with other commands. When no 'old_target' is provided it can also delete regular refs, similar to how the 'delete' command can delete symrefs when no 'old_oid' is provided. Helped-by: Patrick Steinhardt Signed-off-by: Karthik Nayak Signed-off-by: Junio C Hamano --- Documentation/git-update-ref.txt | 5 +++ builtin/fetch.c | 4 +- builtin/receive-pack.c | 3 +- builtin/update-ref.c | 33 +++++++++++++++- refs.c | 14 +++++-- refs.h | 4 +- t/t1400-update-ref.sh | 68 ++++++++++++++++++++++++++++++++ t/t1416-ref-transaction-hooks.sh | 19 ++++++++- 8 files changed, 140 insertions(+), 10 deletions(-) diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt index 9fe78b3501..16e02f6979 100644 --- a/Documentation/git-update-ref.txt +++ b/Documentation/git-update-ref.txt @@ -65,6 +65,7 @@ performs all modifications together. Specify commands of the form: create SP SP LF delete SP [SP ] LF verify SP [SP ] LF + symref-delete SP [SP ] LF symref-verify SP [SP ] LF option SP LF start LF @@ -87,6 +88,7 @@ quoting: create SP NUL NUL delete SP NUL [] NUL verify SP NUL [] NUL + symref-delete SP [NUL ] NUL symref-verify SP [NUL ] NUL option SP NUL start NUL @@ -119,6 +121,9 @@ verify:: Verify against but do not change it. If is zero or missing, the ref must not exist. +symref-delete:: + Delete after verifying it exists with , if given. + symref-verify:: Verify symbolic against but do not change it. If is missing, the ref must not exist. Can only be diff --git a/builtin/fetch.c b/builtin/fetch.c index 66840b7c5b..ef286a4a4c 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -1382,8 +1382,8 @@ static int prune_refs(struct display_state *display_state, if (!dry_run) { if (transaction) { for (ref = stale_refs; ref; ref = ref->next) { - result = ref_transaction_delete(transaction, ref->name, NULL, 0, - "fetch: prune", &err); + result = ref_transaction_delete(transaction, ref->name, NULL, + NULL, 0, "fetch: prune", &err); if (result) goto cleanup; } diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c index b150ef39a8..64f82612c7 100644 --- a/builtin/receive-pack.c +++ b/builtin/receive-pack.c @@ -1576,7 +1576,8 @@ static const char *update(struct command *cmd, struct shallow_info *si) if (ref_transaction_delete(transaction, namespaced_name, old_oid, - 0, "push", &err)) { + NULL, 0, + "push", &err)) { rp_error("%s", err.buf); ret = "failed to delete"; } else { diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 6dce1cd663..833ebbdd42 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -293,7 +293,7 @@ static void parse_cmd_delete(struct ref_transaction *transaction, if (ref_transaction_delete(transaction, refname, have_old ? &old_oid : NULL, - update_flags, msg, &err)) + NULL, update_flags, msg, &err)) die("%s", err.buf); update_flags = default_flags; @@ -301,6 +301,36 @@ static void parse_cmd_delete(struct ref_transaction *transaction, strbuf_release(&err); } + +static void parse_cmd_symref_delete(struct ref_transaction *transaction, + const char *next, const char *end) +{ + struct strbuf err = STRBUF_INIT; + char *refname, *old_target; + + if (!(update_flags & REF_NO_DEREF)) + die("symref-delete: cannot operate with deref mode"); + + refname = parse_refname(&next); + if (!refname) + die("symref-delete: missing "); + + old_target = parse_next_refname(&next); + + if (*next != line_termination) + die("symref-delete %s: extra input: %s", refname, next); + + if (ref_transaction_delete(transaction, refname, NULL, + old_target, update_flags, msg, &err)) + die("%s", err.buf); + + update_flags = default_flags; + free(refname); + free(old_target); + strbuf_release(&err); +} + + static void parse_cmd_verify(struct ref_transaction *transaction, const char *next, const char *end) { @@ -443,6 +473,7 @@ static const struct parse_cmd { { "create", parse_cmd_create, 2, UPDATE_REFS_OPEN }, { "delete", parse_cmd_delete, 2, UPDATE_REFS_OPEN }, { "verify", parse_cmd_verify, 2, UPDATE_REFS_OPEN }, + { "symref-delete", parse_cmd_symref_delete, 2, UPDATE_REFS_OPEN }, { "symref-verify", parse_cmd_symref_verify, 2, UPDATE_REFS_OPEN }, { "option", parse_cmd_option, 1, UPDATE_REFS_OPEN }, { "start", parse_cmd_start, 0, UPDATE_REFS_STARTED }, diff --git a/refs.c b/refs.c index 865264d487..8114bf65e0 100644 --- a/refs.c +++ b/refs.c @@ -979,7 +979,7 @@ int refs_delete_ref(struct ref_store *refs, const char *msg, transaction = ref_store_transaction_begin(refs, &err); if (!transaction || ref_transaction_delete(transaction, refname, old_oid, - flags, msg, &err) || + NULL, flags, msg, &err) || ref_transaction_commit(transaction, &err)) { error("%s", err.buf); ref_transaction_free(transaction); @@ -1317,14 +1317,20 @@ int ref_transaction_create(struct ref_transaction *transaction, int ref_transaction_delete(struct ref_transaction *transaction, const char *refname, const struct object_id *old_oid, - unsigned int flags, const char *msg, + const char *old_target, + unsigned int flags, + const char *msg, struct strbuf *err) { if (old_oid && is_null_oid(old_oid)) BUG("delete called with old_oid set to zeros"); + if (old_oid && old_target) + BUG("delete called with both old_oid and old_target set"); + if (old_target && !(flags & REF_NO_DEREF)) + BUG("delete cannot operate on symrefs with deref mode"); return ref_transaction_update(transaction, refname, null_oid(), old_oid, - NULL, NULL, flags, + NULL, old_target, flags, msg, err); } @@ -2767,7 +2773,7 @@ int refs_delete_refs(struct ref_store *refs, const char *logmsg, for_each_string_list_item(item, refnames) { ret = ref_transaction_delete(transaction, item->string, - NULL, flags, msg, &err); + NULL, NULL, flags, msg, &err); if (ret) { warning(_("could not delete reference %s: %s"), item->string, err.buf); diff --git a/refs.h b/refs.h index 48cec1ba72..5b84958528 100644 --- a/refs.h +++ b/refs.h @@ -767,7 +767,9 @@ int ref_transaction_create(struct ref_transaction *transaction, int ref_transaction_delete(struct ref_transaction *transaction, const char *refname, const struct object_id *old_oid, - unsigned int flags, const char *msg, + const char *old_target, + unsigned int flags, + const char *msg, struct strbuf *err); /* diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh index 07e111b063..2ddc586d5d 100755 --- a/t/t1400-update-ref.sh +++ b/t/t1400-update-ref.sh @@ -1729,6 +1729,74 @@ do test_cmp expect actual ' + test_expect_success "stdin $type symref-delete fails without --no-deref" ' + git symbolic-ref refs/heads/symref $a && + format_command $type "symref-delete refs/heads/symref" "$a" >stdin && + test_must_fail git update-ref --stdin $type err && + grep "fatal: symref-delete: cannot operate with deref mode" err + ' + + test_expect_success "stdin $type symref-delete fails with no ref" ' + format_command $type "symref-delete " >stdin && + test_must_fail git update-ref --stdin $type --no-deref err && + grep "fatal: symref-delete: missing " err + ' + + test_expect_success "stdin $type symref-delete fails deleting regular ref" ' + test_when_finished "git update-ref -d refs/heads/regularref" && + git update-ref refs/heads/regularref $a && + format_command $type "symref-delete refs/heads/regularref" "$a" >stdin && + test_must_fail git update-ref --stdin $type --no-deref err && + grep "fatal: cannot lock ref ${SQ}refs/heads/regularref${SQ}: expected symref with target ${SQ}$a${SQ}: but is a regular ref" err + ' + + test_expect_success "stdin $type symref-delete fails with too many arguments" ' + format_command $type "symref-delete refs/heads/symref" "$a" "$a" >stdin && + test_must_fail git update-ref --stdin $type --no-deref err && + if test "$type" = "-z" + then + grep "fatal: unknown command: $a" err + else + grep "fatal: symref-delete refs/heads/symref: extra input: $a" err + fi + ' + + test_expect_success "stdin $type symref-delete fails with wrong old value" ' + format_command $type "symref-delete refs/heads/symref" "$m" >stdin && + test_must_fail git update-ref --stdin $type --no-deref err && + grep "fatal: verifying symref target: ${SQ}refs/heads/symref${SQ}: is at $a but expected refs/heads/main" err && + git symbolic-ref refs/heads/symref >expect && + echo $a >actual && + test_cmp expect actual + ' + + test_expect_success "stdin $type symref-delete works with right old value" ' + format_command $type "symref-delete refs/heads/symref" "$a" >stdin && + git update-ref --stdin $type --no-deref stdin && + format_command $type "symref-delete refs/heads/symref" "" >stdin && + git update-ref --stdin $type --no-deref stdin && + git update-ref --stdin $type --no-deref stdin && + git update-ref --stdin $type --no-deref >actual @@ -171,16 +172,32 @@ test_expect_success 'hook gets all queued symref updates' ' done >>actual EOF - cat >expect <<-EOF && + # In the files backend, "delete" also triggers an additional transaction + # update on the packed-refs backend, which constitutes additional reflog + # entries. + if test_have_prereq REFFILES + then + cat >expect <<-EOF + aborted + $ZERO_OID $ZERO_OID refs/heads/symrefd + EOF + else + >expect + fi && + + cat >>expect <<-EOF && prepared ref:refs/heads/main $ZERO_OID refs/heads/symref + ref:refs/heads/main $ZERO_OID refs/heads/symrefd committed ref:refs/heads/main $ZERO_OID refs/heads/symref + ref:refs/heads/main $ZERO_OID refs/heads/symrefd EOF git update-ref --no-deref --stdin <<-EOF && start symref-verify refs/heads/symref refs/heads/main + symref-delete refs/heads/symrefd refs/heads/main prepare commit EOF