FD_ISSET requires that the fd being tested is >= 0 (#78)

* FD_ISSET requires that the fd being tested is >= 0, so unset fd -1 causes trouble.

* Remove code to enable X I/O signal generation from xinit.c

If the I/O signals are enabled before the signal handler has
been set up, the default action on receipt of a SIGPOLL or SIGIO
will be that the program exits.  For now, turn the signals off,
as they aren't necessary and may not even be an improvement.

* Ensure fds are declared as signed and initialized (to -1)

The global fds may be accessed from the signal handler before any
particular device has been opened.  Ensure that the fds are initialized
statically and that the value is distinguishable from all valid descriptors.

	modified:   initdsp.c
	modified:   initkbd.c
	modified:   keyevent.c
	modified:   osmsg.c
	modified:   rs232c.c
	modified:   timer.c
	modified:   tty.c

src/initdsp.c

@@ -108,8 +108,8 @@ int oldred[2], oldgreen[2], oldblue[2];
 #endif /* DISPLAYBUFFER */
 #endif /* NOPIXRECT */
 
-int LispWindowFd;
-int FrameBufferFd;
+int LispWindowFd = -1;
+int FrameBufferFd = -1;
 
 int displaywidth, displayheight, DisplayRasterWidth, DisplayType;
 int DisplayByteSize;

src/initkbd.c

@@ -123,7 +123,7 @@ extern struct screen LispScreen;
 #endif /* SUNDISPLAY */
 
 extern int LispWindowFd;
-int LispKbdFd;
+int LispKbdFd = -1;
 extern int errno;
 
 /*   for debug    */

src/keyevent.c

@@ -124,11 +124,11 @@ extern fd_set LispIOFds;
 fd_set LispReadFds;
 int XNeedSignal = 0; /* T if an X interrupt happened while XLOCK asserted */
 
+extern int LogFileFd;
+
 #ifdef NOETHER
-extern u_int LogFileFd;
 #else
 extern int ether_fd;
-extern u_int LogFileFd;
 #endif /* NOETHER */
 
 extern DLword *DisplayRegion68k;
@@ -316,7 +316,7 @@ getmore:
       */
 
 #ifdef SUNDISPLAY
-    if (FD_ISSET(LispWindowFd, &rfds)) {
+    if (LispWindowFd >= 0 && FD_ISSET(LispWindowFd, &rfds)) {
       /* #endif */
       while (input_readevent(LispWindowFd, &event) >= 0) {
         /*if(!kb_event( &event )) {goto getmore;};*/
@@ -341,19 +341,19 @@ getmore:
 
 #ifdef NOETHER
 #else
-    if (FD_ISSET(ether_fd, &rfds)) { /* Raw ethernet (NIT) I/O happened, so handle it. */
+    if (ether_fd >= 0 && FD_ISSET(ether_fd, &rfds)) { /* Raw ethernet (NIT) I/O happened, so handle it. */
       DBPRINT(("Handling enet interrupt.\n\n"));
       check_ether();
     }
 #endif /* NOETHER */
 
 #ifdef RS232
-    if (FD_ISSET(RS232C_Fd, &rfds) || (RS232C_remain_data && rs232c_lisp_is_ready()))
+    if (RS232C_Fd >= 0 && (FD_ISSET(RS232C_Fd, &rfds) || (RS232C_remain_data && rs232c_lisp_is_ready())))
       rs232c_read();
 #endif /* RS232 */
 
 #ifdef LOGINT
-    if (FD_ISSET(LogFileFd, &rfds)) { /* There's info in the log file.  Tell Lisp to print it. */
+    if (LogFileFd >= 0 && FD_ISSET(LogFileFd, &rfds)) { /* There's info in the log file.  Tell Lisp to print it. */
       flush_pty();          /* move the msg(s) to the log file */
 
       ((INTSTAT *)Addr68k_from_LADDR(*INTERRUPTSTATE_word))->LogFileIO = 1;

src/osmsg.c

@@ -64,7 +64,7 @@ int log_id;
 int previous_size;
 int logChanged; /* T if log file has changed since last READ */
                 /* Set by flush_pty, to avoid the stat call  */
-u_int LogFileFd;
+int LogFileFd = -1;
 extern fd_set LispReadFds;
 
 /************************************************************************/

src/rs232c.c

@@ -29,7 +29,7 @@ static DLword *RS232CGetCSB, *RS232CPutCSB;
  * File descriptor
  */
 extern fd_set LispReadFds;
-int RS232C_Fd;
+int RS232C_Fd = -1;
 
 int RS232C_remain_data;
 static char *RS232C_Dev;

src/timer.c

@@ -460,7 +460,7 @@ int TIMER_INTERVAL = 25000;
 
 int FileIOFlag = 0;
 int TimerFlag = 0;
-extern u_int LispWindowFd;
+extern int LispWindowFd;
 
 /************************************************************************/
 /*									*/

src/tty.c

@@ -18,7 +18,7 @@ DLTTY_IN_CSB *DLTTYIn;
 DLTTY_OUT_CSB *DLTTYOut;
 
 char *TTY_Dev;
-int TTY_Fd;
+int TTY_Fd = -1;
 extern fd_set LispReadFds;
 struct sgttyb TTY_Mode;
 

src/xinit.c

@@ -99,9 +99,6 @@ void init_Xevent(DspInterface dsp)
   XSelectInput(dsp->display_id, dsp->SWGrav, GravMask);
   XSelectInput(dsp->display_id, dsp->NWGrav, GravMask);
 
-#if defined(OS5) && defined(I_SETSIG)
-  ioctl(ConnectionNumber(dsp->display_id), I_SETSIG, S_INPUT); /* so we see X events fast */
-#endif
 } /*end init_Xevent */
 
 /************************************************************************/