worktree: teach worktree_lock_reason() to gently handle main worktree

worktree_lock_reason() aborts with an assertion failure when called on
the main worktree since locking the main worktree is nonsensical. Not
only is this behavior undocumented, thus callers might not even be aware
that the call could potentially crash the program, but it also forces
clients to be extra careful:

    if (!is_main_worktree(wt) && worktree_locked_reason(...))
        ...

Since we know that locking makes no sense in the context of the main
worktree, we can simply return false for the main worktree, thus making
client code less complex by eliminating the need for the callers to have
inside knowledge about the implementation:

    if (worktree_lock_reason(...))
        ...

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Rafael Silva 2021-01-19 22:27:35 +01:00 committed by Junio C Hamano
parent fc0c7d5e9e
commit eb36135af7
2 changed files with 3 additions and 2 deletions

View File

@ -604,7 +604,7 @@ static void show_worktree(struct worktree *wt, int path_maxlen, int abbrev_len)
strbuf_addstr(&sb, "(error)");
}
if (!is_main_worktree(wt) && worktree_lock_reason(wt))
if (worktree_lock_reason(wt))
strbuf_addstr(&sb, " locked");
printf("%s\n", sb.buf);

View File

@ -225,7 +225,8 @@ int is_main_worktree(const struct worktree *wt)
const char *worktree_lock_reason(struct worktree *wt)
{
assert(!is_main_worktree(wt));
if (is_main_worktree(wt))
return NULL;
if (!wt->lock_reason_valid) {
struct strbuf path = STRBUF_INIT;