Unexpected usage of 'duplicate' flag in sapi_add_header_ex()

Hi gurus. Fiddling with PHP extensions I found the following code in 'sapi_add_header_ex()' in SAPI.c if (!duplicate)

      efree(header_line);

which makes me wonder because the other day I read CODING_STANDARD included in PHP src which says "[1] Functions that are given pointers to resources should not free them *snip* Exceptions: - The function's designated behavior is freeing that resource. E.g. efree() - The function is given a boolean argument, that controls whether or not the function may free its arguments (if true - the function must free its arguments, if false - it must not) *snip* " I felt the rule above is incompatible with how efree and duplicate flag is used in sapi_add_header_ex(). So my question is... Is this intentional? If so, any reason to break the coding standard in this instance? and what does, in this context, 'duplicate' means? Thanks you in advance.