[Dovecot] Possible bug in Maildir++ quota?

[Ulrich Zehl]

While researching a possible bug in our custom-made Maildir++ expiration
script, I found the following in src/plugins/quota/quota-maildir.c. 

| static const char *
| maildir_list_next(struct maildir_list_context *ctx, time_t *mtime_r)
| {
| [...]
|       *mtime_r = st.st_size;
|       return str_c(ctx->path);
| }

As far as I unterstand, this seems incorrect, because the value in mtime_r
is used, for example, in maildirs_check_have_changed to check whether any
maildirs or folders have changed.

If this isn't a bug, please satisfy my own curiosity and tell me what I'm
missing.

Ulrich