David TurnerIt is possible to have two refs which are the same but for case. This works great on the case-sensitive filesystems, but not so well on case-insensitive filesystems. It is fairly typical to have case-insensitive clients (Macs, say) with a case-sensitive server (GNU/Linux).
Should a user attempt to pull on a Mac when there are case clone refs with differing contents, they'll get an error message containing something like "Ref refs/remotes/origin/lower is at [sha-of-lowercase-ref] but expected [sha-of-uppercase-ref].... (unable to update local ref)"
With a case-insensitive git server, if a branch called capital-M Master (that differs from lowercase-m-master) is pushed, nobody else can push to (lowercase-m) master until the branch is removed.
Create the option receive.denycaseclonerefs, which checks pushed refs to ensure that they are not case clones of an existing ref. This setting is turned on by default if core.ignorecase is set, but not otherwise.
Signed-off-by: David Turner <dturner@twitter.com> --- Documentation/config.txt | 6 +++++ Documentation/git-push.txt | 5 +++-- Documentation/glossary-content.txt | 5 +++++ builtin/receive-pack.c | 27 +++++++++++++++++++++- t/t5400-send-pack.sh | 46 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 86 insertions(+), 3 deletions(-)
Show changes to 5 files +86 −3
Documentation/config.txt, Documentation/git-push.txt, Documentation/glossary-content.txt, builtin/receive-pack.c, t/t5400-send-pack.sh
diff --git a/Documentation/config.txt b/Documentation/config.txt index 1932e9b..b24b117 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -2053,6 +2053,12 @@ receive.unpackLimit:: especially on slow filesystems. If not set, the value of `transfer.unpackLimit` is used instead. +receive.denyCaseCloneRefs:: + If set to true, git-receive-pack will deny a ref update that creates + a ref which is the same but for case as an existing ref. This is + useful when clients are on a case-insensitive filesystem, which + will cause errors when given refs which differ only in case. + receive.denyDeletes:: If set to true, git-receive-pack will deny a ref update that deletes the ref. Use this to prevent such a ref deletion via a push. diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt index 21cd455..c92c3a6 100644 --- a/Documentation/git-push.txt +++ b/Documentation/git-push.txt @@ -323,8 +323,9 @@ remote rejected:: of the following safety options in effect: `receive.denyCurrentBranch` (for pushes to the checked out branch), `receive.denyNonFastForwards` (for forced - non-fast-forward updates), `receive.denyDeletes` or - `receive.denyDeleteCurrent`. See linkgit:git-config[1]. + non-fast-forward updates), `receive.denyDeletes`, + `receive.denyCaseCloneRefs` or `receive.denyDeleteCurrent`. + See linkgit:git-config[1]. remote failure:: The remote end did not report the successful update of the ref, diff --git a/Documentation/glossary-content.txt b/Documentation/glossary-content.txt index be0858c..ed5ac23 100644 --- a/Documentation/glossary-content.txt +++ b/Documentation/glossary-content.txt @@ -31,6 +31,11 @@ [[def_cache]]cache:: Obsolete for: <<def_index,index>>. +[[def_case_clone]]case clone:: + Two entities (e.g. filenames or refs) that differ only in case. + These can cause problems on case-insensitive filesystems, and + Git has machinery to prevent these problems in various cases. + [[def_chain]]chain:: A list of objects, where each <<def_object,object>> in the list contains a reference to its successor (for example, the successor of a diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c index c323081..8530a6c 100644 --- a/builtin/receive-pack.c +++ b/builtin/receive-pack.c @@ -27,6 +27,7 @@ enum deny_action { static int deny_deletes; static int deny_non_fast_forwards; +static int deny_case_clone_refs = DENY_UNCONFIGURED; static enum deny_action deny_current_branch = DENY_UNCONFIGURED; static enum deny_action deny_delete_current = DENY_UNCONFIGURED; static int receive_fsck_objects = -1; @@ -69,6 +70,11 @@ static int receive_pack_config(const char *var, const char *value, void *cb) if (status) return status; + if (strcmp(var, "receive.denycaseclonerefs") == 0) { + deny_case_clone_refs = parse_deny_action(var, value); + return 0; + } + if (strcmp(var, "receive.denydeletes") == 0) { deny_deletes = git_config_bool(var, value); return 0; @@ -468,6 +474,22 @@ static int update_shallow_ref(struct command *cmd, struct shallow_info *si) return 0; } +static int is_case_clone(const char *refname, const unsigned char *sha1, + int flags, void *cb_data) +{ + const char *incoming_refname = cb_data; + return !strcasecmp(refname, incoming_refname) && + strcmp(refname, incoming_refname); +} + +static int ref_is_denied_case_clone(const char *name) +{ + if (!deny_case_clone_refs) + return 0; + + return for_each_ref(is_case_clone, (void *) name); +} + static const char *update(struct command *cmd, struct shallow_info *si) { const char *name = cmd->ref_name; @@ -478,7 +500,8 @@ static const char *update(struct command *cmd, struct shallow_info *si) struct ref_lock *lock; /* only refs/... are allowed */ - if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) { + if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0) || + ref_is_denied_case_clone(name)) { rp_error("refusing to create funny ref '%s' remotely", name); return "funny refname"; } @@ -1171,6 +1194,8 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix) die("'%s' does not appear to be a git repository", dir); git_config(receive_pack_config, NULL); + if (deny_case_clone_refs == DENY_UNCONFIGURED) + deny_case_clone_refs = ignore_case; if (0 <= transfer_unpack_limit) unpack_limit = transfer_unpack_limit; diff --git a/t/t5400-send-pack.sh b/t/t5400-send-pack.sh index 0736bcb..a7023dc 100755 --- a/t/t5400-send-pack.sh +++ b/t/t5400-send-pack.sh @@ -129,6 +129,52 @@ test_expect_success 'denyNonFastforwards trumps --force' ' test "$victim_orig" = "$victim_head" ' +test_expect_success 'denyCaseCloneRefs works' ' + ( + cd victim && + git config receive.denyCaseCloneRefs true && + git config receive.denyDeletes false + ) && + git send-pack ./victim HEAD:refs/heads/caseclone && + orig_ver=$(git rev-parse HEAD) && + test_must_fail git send-pack ./victim HEAD^:refs/heads/CaseClone && + # confirm that this had no effect upstream + ( + cd victim && + ref=$(git for-each-ref --format="%(refname)" refs/heads/CaseClone) && + echo "$ref" | test_must_fail grep -q CaseClone && + remote_ver=$(git rev-parse caseclone) && + test "$orig_ver" = "$remote_ver" + ) && + git send-pack ./victim HEAD^:refs/heads/notacaseclone && + test_must_fail git send-pack ./victim :CaseClone && + # confirm that this had no effect upstream + ( + cd victim && + ref=$(git for-each-ref --format="%(refname)" refs/heads/CaseClone) && + echo "$ref" | test_must_fail grep -q CaseClone && + remote_ver=$(git rev-parse caseclone) && + test "$orig_ver" = "$remote_ver" + ) && + git send-pack ./victim :caseclone && + # confirm that this took effect upstream + ( + cd victim && + test_must_fail git rev-parse caseclone + ) && + # check that we can recreate a branch after deleting a + # case-clone of it + case_clone_ver=$(git rev-parse HEAD^) && + git send-pack ./victim HEAD^:refs/heads/CaseClone && + ( + cd victim && + ref=$(git for-each-ref --format="%(refname)" refs/heads/caseclone) && + test_echo "$ref" | test_must_fail grep -q caseclone && + remote_ver=$(git rev-parse CaseClone) && + test "$case_clone_ver" = "$remote_ver" + ) +' + test_expect_success 'push --all excludes remote-tracking hierarchy' ' mkdir parent && (
-- 2.0.0.rc1.24.g0588c94.dirty
