Will strings in auto_string be freed if CONFIG_FEATURE_CLEAN_UP is enabled?

[versaloon]

I'm using busybox in a memory constrained hardware with 320K bytes heap, so CONFIG_FEATURE_CLEAN_UP is enabed.

But I found there is some memory leakage when using auto_string, after looking into the source code, I found that the allocated string stored in auto_string will not be freed, is that true or any fix available to this problem?