From 12fd3496d19c33c6401c5fdc7558944d46124a0f Mon Sep 17 00:00:00 2001 From: David Turner Date: Wed, 24 Feb 2016 17:58:51 -0500 Subject: [PATCH] refs: don't dereference on rename When renaming refs, don't dereference either the origin or the destination before renaming. The origin does not need to be dereferenced because it is presently forbidden to rename symbolic refs. Not dereferencing the destination fixes a bug where renaming on top of a broken symref would use the pointed-to ref name for the moved reflog. Add a test for the reflog bug. Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty --- refs/files-backend.c | 21 ++++++++++++++++----- t/t3200-branch.sh | 9 +++++++++ 2 files changed, 25 insertions(+), 5 deletions(-) diff --git a/refs/files-backend.c b/refs/files-backend.c index 2f98eebe94..15ba456d68 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -2333,7 +2333,8 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms if (log && S_ISLNK(loginfo.st_mode)) return error("reflog for %s is a symlink", oldrefname); - if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, orig_sha1, &flag)) + if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, + orig_sha1, &flag)) return error("refname %s not found", oldrefname); if (flag & REF_ISSYMREF) @@ -2351,8 +2352,16 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms goto rollback; } - if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) && - delete_ref(newrefname, sha1, REF_NODEREF)) { + /* + * Since we are doing a shallow lookup, sha1 is not the + * correct value to pass to delete_ref as old_sha1. But that + * doesn't matter, because an old_sha1 check wouldn't add to + * the safety anyway; we want to delete the reference whatever + * its current value. + */ + if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, + sha1, NULL) && + delete_ref(newrefname, NULL, REF_NODEREF)) { if (errno==EISDIR) { struct strbuf path = STRBUF_INIT; int result; @@ -2376,7 +2385,8 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms logmoved = log; - lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err); + lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF, + NULL, &err); if (!lock) { error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); strbuf_release(&err); @@ -2394,7 +2404,8 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms return 0; rollback: - lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err); + lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF, + NULL, &err); if (!lock) { error("unable to lock %s for rollback: %s", oldrefname, err.buf); strbuf_release(&err); diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh index f3e3b6cf2e..42811604bb 100755 --- a/t/t3200-branch.sh +++ b/t/t3200-branch.sh @@ -79,6 +79,15 @@ test_expect_success 'git branch -m dumps usage' ' test_i18ngrep "branch name required" err ' +test_expect_success 'git branch -m m broken_symref should work' ' + test_when_finished "git branch -D broken_symref" && + git branch -l m && + git symbolic-ref refs/heads/broken_symref refs/heads/i_am_broken && + git branch -m m broken_symref && + git reflog exists refs/heads/broken_symref && + test_must_fail git reflog exists refs/heads/i_am_broken +' + test_expect_success 'git branch -m m m/m should work' ' git branch -l m && git branch -m m m/m &&