From: Jonathan Nieder <jrnieder@xxxxxxxxx>
Date: Wed, 10 Sep 2014 18:22:48 -0700
If a repository gets in a broken state with too much symref nesting,
it cannot be repaired with "git branch -d":
$ git symbolic-ref refs/heads/nonsense refs/heads/nonsense
$ git branch -d nonsense
error: branch 'nonsense' not found.
Worse, "git update-ref --no-deref -d" doesn't work for such repairs
either:
$ git update-ref -d refs/heads/nonsense
error: unable to resolve reference refs/heads/nonsense: Too many levels of symbolic links
Fix both by teaching resolve_ref_unsafe a new RESOLVE_REF_NO_RECURSE
flag and passing it when appropriate.
Callers can still read the value of a symref (for example to print a
message about it) with that flag set --- resolve_ref_unsafe will
resolve one level of symrefs and stop there.
Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
Reviewed-by: Ronnie Sahlberg <sahlberg@xxxxxxxxxx>
---
Since v21:
- renamed flag from RESOLVE_REF_NO_DEREF to _NO_RECURSE
- more detail in API docs
- only set NO_RECURSE when deleting refs. Locking refs for non-deletion
updates needs to recurse to get old_sha1 for the reflog.
- add more tests (for symrefs to refs with bad names, which should also
be deletable now)
builtin/branch.c | 3 ++-
cache.h | 6 ++++++
refs.c | 17 +++++++++++++++--
refs.h | 2 ++
t/t1400-update-ref.sh | 34 ++++++++++++++++++++++++++++++++++
t/t3200-branch.sh | 9 +++++++++
6 files changed, 68 insertions(+), 3 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index e5d1377..a334380 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -234,7 +234,8 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
free(name);
name = mkpathdup(fmt, bname.buf);
- target = resolve_ref_unsafe(name, 0, sha1, &flags);
+ target = resolve_ref_unsafe(name, RESOLVE_REF_NO_RECURSE,
+ sha1, &flags);
if (!target ||
(!(flags & REF_ISSYMREF) && is_null_sha1(sha1))) {
error(remote_branch
diff --git a/cache.h b/cache.h
index 5b54911..5ca7f2b 100644
--- a/cache.h
+++ b/cache.h
@@ -970,6 +970,11 @@ extern int read_ref(const char *refname, unsigned char *sha1);
* "writing" to the ref, the return value is the name of the ref
* that will actually be created or changed.
*
+ * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
+ * level of symbolic reference. The value stored in sha1 for a symbolic
+ * reference will always be null_sha1 in this case, and the return
+ * value is the reference that the symref refers to directly.
+ *
* If flags is non-NULL, set the value that it points to the
* combination of REF_ISPACKED (if the reference was found among the
* packed references), REF_ISSYMREF (if the initial reference was a
@@ -982,6 +987,7 @@ extern int read_ref(const char *refname, unsigned char *sha1);
* errno is set to something meaningful on error.
*/
#define RESOLVE_REF_READING 0x01
+#define RESOLVE_REF_NO_RECURSE 0x02
extern const char *resolve_ref_unsafe(const char *ref, int resolve_flags, unsigned char *sha1, int *flags);
extern char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags);
diff --git a/refs.c b/refs.c
index 4916d16..490e788 100644
--- a/refs.c
+++ b/refs.c
@@ -1407,6 +1407,10 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
refname = refname_buffer;
if (flags)
*flags |= REF_ISSYMREF;
+ if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
+ hashclr(sha1);
+ return refname;
+ }
continue;
}
}
@@ -1463,13 +1467,17 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
buf = buffer + 4;
while (isspace(*buf))
buf++;
+ refname = strcpy(refname_buffer, buf);
+ if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
+ hashclr(sha1);
+ return refname;
+ }
if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
if (flags)
*flags |= REF_ISBROKEN;
errno = EINVAL;
return NULL;
}
- refname = strcpy(refname_buffer, buf);
}
}
@@ -2111,6 +2119,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
if (mustexist)
resolve_flags |= RESOLVE_REF_READING;
+ if (flags & REF_NODEREF && flags & REF_DELETING)
+ resolve_flags |= RESOLVE_REF_NO_RECURSE;
refname = resolve_ref_unsafe(refname, resolve_flags,
lock->old_sha1, &type);
@@ -3610,13 +3620,16 @@ int ref_transaction_commit(struct ref_transaction *transaction,
/* Acquire all locks while verifying old values */
for (i = 0; i < n; i++) {
struct ref_update *update = updates[i];
+ int flags = update->flags;
+ if (is_null_sha1(update->new_sha1))
+ flags |= REF_DELETING;
update->lock = lock_ref_sha1_basic(update->refname,
(update->have_old ?
update->old_sha1 :
NULL),
NULL,
- update->flags,
+ flags,
&update->type);
if (!update->lock) {
ret = (errno == ENOTDIR)
diff --git a/refs.h b/refs.h
index 3bb16db..b62c4c4 100644
--- a/refs.h
+++ b/refs.h
@@ -175,10 +175,12 @@ extern int peel_ref(const char *refname, unsigned char *sha1);
* ref_transaction_create(), etc.
* REF_NODEREF: act on the ref directly, instead of dereferencing
* symbolic references.
+ * REF_DELETING: tolerate broken refs
*
* Flags >= 0x100 are reserved for internal use.
*/
#define REF_NODEREF 0x01
+#define REF_DELETING 0x02
/*
* This function sets errno to something meaningful on failure.
*/
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 0218e96..7c8c41a 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -110,6 +110,40 @@ test_expect_success "delete symref without dereference when the referred ref is
cp -f .git/HEAD.orig .git/HEAD
git update-ref -d $m
+test_expect_success 'update-ref -d is not confused by self-reference' '
+ git symbolic-ref refs/heads/self refs/heads/self &&
+ test_when_finished "rm -f .git/refs/heads/self" &&
+ test_path_is_file .git/refs/heads/self &&
+ test_must_fail git update-ref -d refs/heads/self &&
+ test_path_is_file .git/refs/heads/self
+'
+
+test_expect_success 'update-ref --no-deref -d can delete self-reference' '
+ git symbolic-ref refs/heads/self refs/heads/self &&
+ test_when_finished "rm -f .git/refs/heads/self" &&
+ test_path_is_file .git/refs/heads/self &&
+ git update-ref --no-deref -d refs/heads/self &&
+ test_path_is_missing .git/refs/heads/self
+'
+
+test_expect_success 'update-ref --no-deref -d can delete reference to bad ref' '
+ >.git/refs/heads/bad &&
+ test_when_finished "rm -f .git/refs/heads/bad" &&
+ git symbolic-ref refs/heads/ref-to-bad refs/heads/bad &&
+ test_when_finished "rm -f .git/refs/heads/ref-to-bad" &&
+ test_path_is_file .git/refs/heads/ref-to-bad &&
+ git update-ref --no-deref -d refs/heads/ref-to-bad &&
+ test_path_is_missing .git/refs/heads/ref-to-bad
+'
+
+test_expect_success 'update-ref --no-deref -d can delete reference to broken name' '
+ git symbolic-ref refs/heads/badname refs/heads/broken...ref &&
+ test_when_finished "rm -f .git/refs/heads/badname" &&
+ test_path_is_file .git/refs/heads/badname &&
+ git update-ref --no-deref -d refs/heads/badname &&
+ test_path_is_missing .git/refs/heads/badname
+'
+
test_expect_success '(not) create HEAD with old sha1' "
test_must_fail git update-ref HEAD $A $B
"
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index ac31b71..432921b 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -285,6 +285,15 @@ test_expect_success 'deleting a dangling symref' '
test_i18ncmp expect actual
'
+test_expect_success 'deleting a self-referential symref' '
+ git symbolic-ref refs/heads/self-reference refs/heads/self-reference &&
+ test_path_is_file .git/refs/heads/self-reference &&
+ echo "Deleted branch self-reference (was refs/heads/self-reference)." >expect &&
+ git branch -d self-reference >actual &&
+ test_path_is_missing .git/refs/heads/self-reference &&
+ test_i18ncmp expect actual
+'
+
test_expect_success 'renaming a symref is not allowed' '
git symbolic-ref refs/heads/master2 refs/heads/master &&
test_must_fail git branch -m master2 master3 &&
--
2.1.0.rc2.206.gedb03e5
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