[PATCH v2 03/20] checkout: improve die_if_checked_out() robustness
- From
Eric Sunshine <sunshine@sunshineco.com>
- Date
- Jul 16, 2015, 08:20 UTC
- Message-ID
- <1437034825-32054-4-git-send-email-sunshine@sunshineco.com>
- In-Reply-To
- <1437034825-32054-1-git-send-email-sunshine@sunshineco.com>
die_if_checked_out() is intended to check if the branch about to be checked out is already checked out either in the main worktree or in a linked worktree. However, if .git/worktrees directory does not exist, then it never bothers checking the main worktree, even though the specified branch might indeed be checked out there, which is fragile behavior.
This hasn't been a problem in practice since the current implementation of "git worktree add" (and, earlier, "git checkout --to") always creates .git/worktrees before die_if_checked_out() is called by the child "git checkout" invocation which populates the new worktree.
However, git-worktree will eventually want to call die_if_checked_out() itself rather than only doing so indirectly as a side-effect of invoking git-checkout, and reliance upon order of operations (creating .git/worktrees before checking if a branch is already checked out) is fragile. As a general function, callers should not be expected to abide by this undocumented and unwarranted restriction. Therefore, make die_if_checked_out() more robust by checking the main worktree whether .git/worktrees exists or not.
While here, also move a comment explaining why die_if_checked_out()'s helper parses HEAD manually. Such information resides more naturally with the helper itself rather than at its first point of call.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> ---
Changes since v1: relocate comment; reword commit message.
builtin/checkout.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/builtin/checkout.c b/builtin/checkout.c index e75fb5e..1992c41 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -880,6 +880,11 @@ static void check_linked_checkout(struct branch_info *new, const char *id) struct strbuf gitdir = STRBUF_INIT; const char *start, *end; + /* + * $GIT_COMMON_DIR/HEAD is practically outside + * $GIT_DIR so resolve_ref_unsafe() won't work (it + * uses git_path). Parse the ref ourselves. + */ if (id) strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id); else @@ -916,19 +921,14 @@ static void die_if_checked_out(struct branch_info *new) DIR *dir; struct dirent *d; + check_linked_checkout(new, NULL); + strbuf_addf(&path, "%s/worktrees", get_git_common_dir()); if ((dir = opendir(path.buf)) == NULL) { strbuf_release(&path); return; } - /* - * $GIT_COMMON_DIR/HEAD is practically outside - * $GIT_DIR so resolve_ref_unsafe() won't work (it - * uses git_path). Parse the ref ourselves. - */ - check_linked_checkout(new, NULL); - while ((d = readdir(dir)) != NULL) { if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, "..")) continue;
-- 2.5.0.rc2.378.g0af52e8