ncurses 5.9 - patch 20120211

[ncurses.git] / ncurses / tty / lib_tstp.c

diff --git a/ncurses/tty/lib_tstp.c b/ncurses/tty/lib_tstp.c
index 6ccdfc74a27f631db6244d408dcb8de351fa68f1..36043f8a2b39aeb41d56faf85e06570e3a0e70b5 100644 (file)
--- a/ncurses/tty/lib_tstp.c
+++ b/ncurses/tty/lib_tstp.c
@@ -42,7 +42,7 @@
 
 #include <SigAction.h>
 
-MODULE_ID("$Id: lib_tstp.c,v 1.42 2011/04/16 16:42:10 tom Exp $")
+MODULE_ID("$Id: lib_tstp.c,v 1.45 2011/10/22 15:37:42 tom Exp $")
 
 #if defined(SIGTSTP) && (HAVE_SIGACTION || HAVE_SIGVEC)
 #define USE_SIGTSTP 1
@@ -240,16 +240,19 @@ cleanup(int sig)
     SCREEN *sp = CURRENT_SCREEN;
 
     /*
-     * Actually, doing any sort of I/O from within an signal handler is
-     * "unsafe".  But we'll _try_ to clean up the screen and terminal
-     * settings on the way out.
+     * Much of this is unsafe from a signal handler.  But we'll _try_ to clean
+     * up the screen and terminal settings on the way out.
+     *
+     * There are at least the following problems:
+     * 1) Walking the SCREEN list is unsafe, since all list management
+     *    is done without any signal blocking.
+     * 2) On systems which have REENTRANT turned on, set_term() uses
+     *    _nc_lock_global() which could deadlock or misbehave in other ways.
+     * 3) endwin() calls all sorts of stuff, many of which use stdio or
+     *    other library functions which are clearly unsafe.
      */
     if (!_nc_globals.cleanup_nested++
-       && (sig == SIGINT
-#ifdef SIGQUIT
-           || sig == SIGQUIT
-#endif
-       )) {
+       && (sig == SIGINT || sig == SIGTERM)) {
 #if HAVE_SIGACTION || HAVE_SIGVEC
        sigaction_t act;
        sigemptyset(&act.sa_mask);
@@ -270,11 +273,11 @@ cleanup(int sig)
                set_term(scan);
                NCURSES_SP_NAME(endwin) (NCURSES_SP_ARG);
                if (sp)
-                   sp->_endwin = FALSE;        /* in case we have an atexit! */
+                   sp->_endwin = FALSE;        /* in case of reuse */
            }
        }
     }
-    exit(EXIT_FAILURE);
+    _exit(EXIT_FAILURE);
 }
 
 #if USE_SIGWINCH
@@ -360,7 +363,7 @@ CatchIfDefault(int sig, RETSIGTYPE (*handler) (int))
  * the caller later changes its mind, but that doesn't seem correct.
  */
 NCURSES_EXPORT(void)
-_nc_signal_handler(bool enable)
+_nc_signal_handler(int enable)
 {
     T((T_CALLED("_nc_signal_handler(%d)"), enable));
 #if USE_SIGTSTP                        /* Xenix 2.x doesn't have SIGTSTP, for example */