[PATCH v3] branch: segfault fixes and validation
branch_get() can return NULL (so far on detached HEAD only) but some code paths in builtin/branch.c cannot deal with that and cause segfaults.
While at there, make sure to bail out when the user gives 2 or more branches with --set-upstream-to or --unset-upstream, where only the first branch is processed and the rest silently dropped.
Reported-by: Per Cederqvist <cederp@opera.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
On Sat, Feb 23, 2013 at 3:27 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Instead of asking "Is it detached?", perhaps we can say something
> like "You told me to set the upstream of HEAD to branch X, but " in
> front? At least, that will be a better explanation for the reason
> why the operation is failing.
Fixed.
> What you can do is to have a single helper function that can explain
> why branch_get() returned NULL (or extend branch_get() to serve that
> purpose as well); then you do not have to duplicate the logic twice
> on the caller's side (and there may be other callers that want to do
> the same).
The explanation mentions about the failed operation, which makes a
helper less useful. We could still do the helper, but it may lead to
i18n legos. So no helper in this version.
> The existing test might be wrong, by the way. Your HEAD may point
> at a branch Y but you may not have any commit on it yet, and you may
> want to allow setting the upstream of that to-be-born branch to
> another branch X with "branch --set-upstream-to=X [Y|HEAD]".
It sounds complicated. I think we can revisit it when a user actually
complains about it.
builtin/branch.c | 27 +++++++++++++++++++++++++++
t/t3200-branch.sh | 21 +++++++++++++++++++++
2 files changed, 48 insertions(+)
diff --git a/builtin/branch.c b/builtin/branch.c
index 6371bf9..00d17d2 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -889,6 +889,17 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
} else if (new_upstream) {
struct branch *branch = branch_get(argv[0]);
+ if (argc > 1)
+ die(_("too many branches to set new upstream"));
+
+ if (!branch) {
+ if (!argc || !strcmp(argv[0], "HEAD"))
+ die(_("could not set upstream of HEAD to %s when "
+ "it does not point to any branch."),
+ new_upstream);
+ die(_("no such branch '%s'"), argv[0]);
+ }
+
if (!ref_exists(branch->refname))
die(_("branch '%s' does not exist"), branch->name);
@@ -901,6 +912,16 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
struct branch *branch = branch_get(argv[0]);
struct strbuf buf = STRBUF_INIT;
+ if (argc > 1)
+ die(_("too many branches to unset upstream"));
+
+ if (!branch) {
+ if (!argc || !strcmp(argv[0], "HEAD"))
+ die(_("could not unset upstream of HEAD when "
+ "it does not point to any branch."));
+ die(_("no such branch '%s'"), argv[0]);
+ }
+
if (!branch_has_merge_config(branch)) {
die(_("Branch '%s' has no upstream information"), branch->name);
}
@@ -916,6 +937,12 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
int branch_existed = 0, remote_tracking = 0;
struct strbuf buf = STRBUF_INIT;
+ if (!strcmp(argv[0], "HEAD"))
+ die(_("it does not make sense to create 'HEAD' manually"));
+
+ if (!branch)
+ die(_("no such branch '%s'"), argv[0]);
+
if (kinds != REF_LOCAL_BRANCH)
die(_("-a and -r options to 'git branch' do not make sense with a branch name"));
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index f3e0e4a..12f1e4a 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -42,6 +42,10 @@ test_expect_success \
'git branch a/b/c should create a branch' \
'git branch a/b/c && test_path_is_file .git/refs/heads/a/b/c'
+test_expect_success \
+ 'git branch HEAD should fail' \
+ 'test_must_fail git branch HEAD'
+
cat >expect <<EOF
$_z40 $HEAD $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000 branch: Created from master
EOF
@@ -388,6 +392,14 @@ test_expect_success \
'git tag foobar &&
test_must_fail git branch --track my11 foobar'
+test_expect_success '--set-upstream-to fails on multiple branches' \
+ 'test_must_fail git branch --set-upstream-to master a b c'
+
+test_expect_success '--set-upstream-to fails on detached HEAD' \
+ 'git checkout HEAD^{} &&
+ test_must_fail git branch --set-upstream-to master &&
+ git checkout -'
+
test_expect_success 'use --set-upstream-to modify HEAD' \
'test_config branch.master.remote foo &&
test_config branch.master.merge foo &&
@@ -417,6 +429,15 @@ test_expect_success 'test --unset-upstream on HEAD' \
test_must_fail git branch --unset-upstream
'
+test_expect_success '--unset-upstream should fail on multiple branches' \
+ 'test_must_fail git branch --unset-upstream a b c'
+
+test_expect_success '--unset-upstream should fail on detached HEAD' \
+ 'git checkout HEAD^{} &&
+ test_must_fail git branch --unset-upstream &&
+ git checkout -
+'
+
test_expect_success 'test --unset-upstream on a particular branch' \
'git branch my15
git branch --set-upstream-to master my14 &&
--
1.8.1.2.536.gf441e6d
Per Cederqvist
