To avoid duplications, make sure that we always use zend_strings for bv_val, which seems to be the case.
Then, just store ZSTR_VAL(str) inside bv_val, without duplicating or anything. Then also don't release the strings. Then, on cleanup instead of efree(bv_val) you can do something like this in pseudocode: zend_string_release(ptr - XtOffset(zend_string, val))

To avoid duplications, make sure that we always use zend_strings for bv_val, which seems to be the case. Then, just store ZSTR_VAL(str) inside bv_val, without duplicating or anything. Then also don't release the strings. Then, on cleanup instead of efree(bv_val) you can do something like this in pseudocode: zend_string_release(ptr - XtOffset(zend_string, val))

Okay this is ingenious, I like it, might have a helper function for this tho as it is slightly exotic

I agree with making a helper macro/function to make the conversion. I would also propose to add the macro only to ext/ldap and not to somewhere generic because this is very much a "beware there be dragons" macro.

I have implemented the suggestion and made some follow-up changes.

I think this can be used in more places, but I need to do some preliminary refactorings to be able to use.