When pushing to a remote repo the sending side filters out aliased
updates (e.g., foo:baz bar:baz). However, it is not possible for the
sender to know if two refs are aliased on the receiving side via
symrefs. Here is one such scenario:
$ git init origin
$ (cd origin && touch file && git add file && git commit -a -m intial)
$ git clone --bare origin origin.git
$ rm -rf origin
$ git clone origin.git client
$ git clone --mirror client backup.git &&
$ (cd backup.git && git remote set-head origin --auto)
$ (cd client &&
git remote add --mirror backup ../backup.git &&
echo change1 > file && git commit -a -m change1 &&
git push origin &&
git push backup
)
The push to backup fails with:
Counting objects: 5, done.
Writing objects: 100% (3/3), 244 bytes, done.
Total 3 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (3/3), done.
error: Ref refs/remotes/origin/master is at ef3... but expected 262...
remote: error: failed to lock refs/remotes/origin/master
To ../backup.git
262cd57..ef307ff master -> master
262cd57..ef307ff origin/HEAD -> origin/HEAD
! [remote rejected] origin/master -> origin/master (failed to lock)
error: failed to push some refs to '../backup.git'
The reason is that refs/remotes/origin/HEAD is a symref to
refs/remotes/origin/master, but it is not possible for the sending side
to unambiguously know this.
This commit fixes the issue by having receive-pack ignore any update to
a symref whose target is being identically updated. If a symref and its
target are being updated inconsistently, then the update for both fails
with an error message ("refusing inconsistent update...") to help
diagnose the situation.
Signed-off-by: Jay Soffian <jaysoffian@xxxxxxxxx>
---
builtin/receive-pack.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++-
t/t5516-fetch-push.sh | 45 +++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+), 1 deletions(-)
Changes from v1 (incorporating Junio's feedback):
- Reformatted commit message; minor rewording.
- Detect situation where there is an inconsistent aliased update and
give a better diagnostic than "failed to lock"
- Add additional test case for inconsistent update situation
[
This one is correct, the interdiff from
<1271694343-31876-2-git-send-email-jaysoffian@xxxxxxxxx> is
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 414446b..7b269d2 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -512,6 +512,8 @@ static void check_aliased_update(struct command *cmd, struct string_list *list)
!hashcmp(cmd->new_sha1, dst_cmd->new_sha1))
return;
+ dst_cmd->skip_update = 1;
+
strcpy(cmd_oldh, find_unique_abbrev(cmd->old_sha1, DEFAULT_ABBREV));
strcat(cmd_newh, find_unique_abbrev(cmd->new_sha1, DEFAULT_ABBREV));
strcpy(dst_oldh, find_unique_abbrev(dst_cmd->old_sha1, DEFAULT_ABBREV));
)
]
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index fffb6ea..7b269d2 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -9,6 +9,7 @@
#include "object.h"
#include "remote.h"
#include "transport.h"
+#include "string-list.h"
static const char receive_pack_usage[] = "git receive-pack <git-dir>";
@@ -129,6 +130,7 @@ static void write_head_info(void)
struct command {
struct command *next;
const char *error_string;
+ unsigned int skip_update;
unsigned char old_sha1[20];
unsigned char new_sha1[20];
char ref_name[FLEX_ARRAY]; /* more */
@@ -486,6 +488,63 @@ static void run_update_post_hook(struct command *commands)
}
}
+static void check_aliased_update(struct command *cmd, struct string_list *list)
+{
+ struct string_list_item *item;
+ struct command *dst_cmd;
+ unsigned char sha1[20];
+ char cmd_oldh[41], cmd_newh[41], dst_oldh[41], dst_newh[41];
+ int flag;
+
+ const char *dst_name = resolve_ref(cmd->ref_name, sha1, 0, &flag);
+
+ if (!(flag & REF_ISSYMREF))
+ return;
+
+ if ((item = string_list_lookup(dst_name, list)) == NULL)
+ return;
+
+ cmd->skip_update = 1;
+
+ dst_cmd = (struct command *) item->util;
+
+ if (!hashcmp(cmd->old_sha1, dst_cmd->old_sha1) &&
+ !hashcmp(cmd->new_sha1, dst_cmd->new_sha1))
+ return;
+
+ dst_cmd->skip_update = 1;
+
+ strcpy(cmd_oldh, find_unique_abbrev(cmd->old_sha1, DEFAULT_ABBREV));
+ strcat(cmd_newh, find_unique_abbrev(cmd->new_sha1, DEFAULT_ABBREV));
+ strcpy(dst_oldh, find_unique_abbrev(dst_cmd->old_sha1, DEFAULT_ABBREV));
+ strcat(dst_newh, find_unique_abbrev(dst_cmd->new_sha1, DEFAULT_ABBREV));
+ rp_error("refusing inconsistent update between symref '%s' (%s..%s) and"
+ " its target '%s' (%s..%s)",
+ cmd->ref_name, cmd_oldh, cmd_newh,
+ dst_cmd->ref_name, dst_oldh, dst_newh);
+
+ cmd->error_string = dst_cmd->error_string =
+ "inconsistent aliased update";
+}
+
+static void check_aliased_updates(struct command *commands)
+{
+ struct command *cmd;
+ struct string_list ref_list = { NULL, 0, 0, 0 };
+
+ for (cmd = commands; cmd; cmd = cmd->next) {
+ struct string_list_item *item =
+ string_list_append(cmd->ref_name, &ref_list);
+ item->util = (void *)cmd;
+ }
+ sort_string_list(&ref_list);
+
+ for (cmd = commands; cmd; cmd = cmd->next)
+ check_aliased_update(cmd, &ref_list);
+
+ string_list_clear(&ref_list, 0);
+}
+
static void execute_commands(struct command *commands, const char *unpacker_error)
{
struct command *cmd;
@@ -503,9 +562,11 @@ static void execute_commands(struct command *commands, const char *unpacker_erro
return;
}
+ check_aliased_updates(commands);
+
head_name = resolve_ref("HEAD", sha1, 0, NULL);
- for (cmd = commands; cmd; cmd = cmd->next)
+ for (cmd = commands; cmd && !cmd->skip_update; cmd = cmd->next)
cmd->error_string = update(cmd);
}
@@ -545,6 +606,7 @@ static struct command *read_head_info(void)
hashcpy(cmd->old_sha1, old_sha1);
hashcpy(cmd->new_sha1, new_sha1);
memcpy(cmd->ref_name, line + 82, len - 81);
+ cmd->skip_update = 0;
cmd->error_string = NULL;
cmd->next = NULL;
*p = cmd;
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 2de98e6..bc3f24f 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -660,6 +660,51 @@ test_expect_success 'push with branches containing #' '
git checkout master
'
+test_expect_success 'push into aliased refs (consistent)' '
+ mk_test heads/master &&
+ mk_child child1 &&
+ mk_child child2 &&
+ (cd child1 &&
+ git branch foo &&
+ git symbolic-ref refs/heads/bar refs/heads/foo
+ git config receive.denyCurrentBranch false
+ ) &&
+ (cd child2 &&
+ : >path2 &&
+ git add path2 &&
+ test_tick &&
+ git commit -a -m child2 &&
+ git branch foo &&
+ git branch bar &&
+ git push ../child1 foo bar
+ )
+'
+
+test_expect_success 'push into aliased refs (inconsistent)' '
+ mk_test heads/master &&
+ mk_child child1 &&
+ mk_child child2 &&
+ (cd child1 &&
+ git branch foo &&
+ git symbolic-ref refs/heads/bar refs/heads/foo
+ git config receive.denyCurrentBranch false
+ ) &&
+ (cd child2 &&
+ : >path2 &&
+ git add path2 &&
+ test_tick &&
+ git commit -a -m child2 &&
+ git branch foo &&
+ : >path3 &&
+ git add path3 &&
+ test_tick &&
+ git commit -a -m child2 &&
+ git branch bar &&
+ test_must_fail git push ../child1 foo bar 2>stderr &&
+ grep "refusing inconsistent update" stderr
+ )
+'
+
test_expect_success 'push --porcelain' '
mk_empty &&
echo >.git/foo "To testrepo" &&
--
1.7.0.3.436.g2b878
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