may now be called with an unfinished sbuf. For consistency, copy the related comment from sbuf_delete() to sbuf_clear() and sbuf_len().
Move the helper macros from sbuf.h to sbuf.c Use ints instead of size_ts. Relax the requirements for sbuf_finish(): it is now possible to finish an overflowed buffer. Make sbuf_len() return -1 instead of 0 if the sbuf overflowed. Requested by: gibbs