* alloc.c: #include <signal.h>, but before "config.h".
along with GNU Emacs; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+#include <signal.h>
#include "config.h"
#include "lisp.h"
#ifdef POSIX_SIGNALS
-#include <signal.h>
+/* Don't #include <signal.h>. That header shouldalways be #included
+ before "config.h", because some configuration files (like s/hpux.h)
+ indicate that SIGIO doesn't work by #undef-ing SIGIO. If this file
+ #includes <signal.h>, then that will re-#define SIGIO and confuse
+ things. */
#define SIGMASKTYPE sigset_t