According to comment in 'magic_rsl_add' and to the way 'magic_rsl_printf' manages its buffer, I think that this memory should be apr_pstrdup'ed.
This has been like that forever, but seems broken to me.
* docs/conf/magic: Allow mod_mime_magic to return "audio/x-wav" for WAV files, and omit returning "audio/unknown" for other RIFF format files. Having a MIME type defined on a continuation line *and* the preceding top-level match breaks mod_mime_magic, which treats the second result "printed" as the MIME encoding. Neither audio/x-wav nor audio/unknown are IANA registered, though Firefox and Chrome both appear to recognize the former. Since the RIFF format can contain non-audio media, returning audio/unknown as a fallback for all RIFF files appears to be bogus anyway.