signal() vs sigaction()

[Dirk Laurie <dirk.laurie@...>]

The code for lua.c includes signal.h and contains several references
to signal(). Since I know nothing about this, I have consulted the
manpage for signal(). It starts thus:

      The behavior of signal() varies across UNIX versions, and has also var‐
       ied historically across different versions of Linux.   Avoid  its  use:
       use sigaction(2) instead.  See Portability below.

Is there a good reason, maybe something to do with other systems, why
the Lua source uses signal() rather than sigaction()?