allow async ignored signals to be reset to SIG_DFL; give rl_input_available_hook precedence in readline:rl_gather_tyi

CWRU/CWRU.chlog

@@ -5105,3 +5105,27 @@ lib/readline/{histexpand.c,history.h}
 
 lib/readline/doc/{history.3,hstech.texi}
 	- history_expansion: change description to note new const first arg
+
+				   1/21
+				   ----
+lib/readline/input.c
+	- rl_gather_tyi: move call to rl_input_available_hook to the top,
+	  giving it first shot. There's still no way for it to set chars_avail.
+	  Conditionalize the rest of the input methods based on whether the
+	  result == -1.
+
+lib/readline/rl_private.h
+	- move the decision making about RL_TIMEOUT_USE_SELECT/RL_TIMEOUT_USE_SIGALRM
+	  here from input.c
+
+				   1/23
+				   ----
+trap.c
+	- restore_default_signal: if we have a signal that's not trapped, but
+	  is a signal that is set to SIG_ASYNCSIG, POSIX interp 751 requires
+	  the shell to allow it to be reset to the default, even though it
+	  wasn't already trapped
+
+subst.c
+	- do_assignment_internal: don't allocate new memory for NAME, just
+	  modify and restore it in place

CWRU/misc/sigs.c

@@ -20,16 +20,16 @@
 
 #include <signal.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 extern const char	* const sys_siglist[];
 
 typedef void	sighandler();
 
-main(argc, argv)
-int	argc;
-char	**argv;
+int
+main(int argc, char **argv)
 {
-	register int	i;
+	int	i;
 	sighandler	*h;
 
 	for (i = 1; i < NSIG; i++) {

CWRU/misc/sigstat.c

@@ -26,14 +26,18 @@
 #include <sys/types.h>
 #include <signal.h>
 #include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
 
-extern char	*strrchr();
 static char	*signames[NSIG];
 
 char	*progname;
 
-void	sigstat();
+void	sigstat(int);
+void	init_signames(void);
 
+int
 main(argc, argv)
 int	argc;
 char	**argv;
@@ -83,6 +87,7 @@ int	sig;
 		printf("%s: signal is trapped (?)\n", signame);
 }
 
+void
 init_signames()
 {
 	register int i;

lib/readline/doc/rltech.texi

@@ -476,6 +476,8 @@ The default hook checks @code{rl_instream}; if an application is using a
 different input source, it should set the hook appropriately.
 Readline queries for available input when implementing intra-key-sequence
 timeouts during input and incremental searches.
+This function must return zero if there is no input available, and non-zero
+if input is available.
 This may use an application-specific timeout before returning a value;
 Readline uses the value passed to @code{rl_set_keyboard_input_timeout()}
 or the value of the user-settable @var{keyseq-timeout} variable.

lib/readline/doc/version.texi

@@ -5,7 +5,7 @@ Copyright (C) 1988-2023 Free Software Foundation, Inc.
 @set EDITION 8.2
 @set VERSION 8.2
 
-@set UPDATED 19 January 2023
+@set UPDATED 21 January 2023
 @set UPDATED-MONTH January 2023
 
-@set LASTCHANGE Thu Jan 19 17:22:06 EST 2023
+@set LASTCHANGE Sat Jan 21 17:10:44 EST 2023

lib/readline/input.c

@@ -138,13 +138,7 @@ win32_isatty (int fd)
 
 /* Readline timeouts */
 
-/* I don't know how to set a timeout for _getch() in MinGW32, so we use
-   SIGALRM. */
-#if (defined (HAVE_PSELECT) || defined (HAVE_SELECT)) && !defined (__MINGW32__)
-#  define RL_TIMEOUT_USE_SELECT
-#else
-#  define RL_TIMEOUT_USE_SIGALRM
-#endif
+/* We now define RL_TIMEOUT_USE_SELECT or RL_TIMEOUT_USE_SIGALRM in rlprivate.h */
 
 int rl_set_timeout (unsigned int, unsigned int);
 int rl_timeout_remaining (unsigned int *, unsigned int *);
@@ -259,38 +253,45 @@ rl_gather_tyi (void)
   input = 0;
   tty = fileno (rl_instream);
 
-#if defined (HAVE_PSELECT) || defined (HAVE_SELECT)
-  FD_ZERO (&readfds);
-  FD_ZERO (&exceptfds);
-  FD_SET (tty, &readfds);
-  FD_SET (tty, &exceptfds);
-  USEC_TO_TIMEVAL (_keyboard_input_timeout, timeout);
-#if defined (RL_TIMEOUT_USE_SELECT)
-  result = _rl_timeout_select (tty + 1, &readfds, (fd_set *)NULL, &exceptfds, &timeout, NULL);
-#else
-  result = select (tty + 1, &readfds, (fd_set *)NULL, &exceptfds, &timeout);
-#endif
-  if (result <= 0)
-    return 0;	/* Nothing to read. */
-#endif
-
-  result = -1;
-  errno = 0;
-#if defined (FIONREAD)
-  result = ioctl (tty, FIONREAD, &chars_avail);
-  if (result == -1 && errno == EIO)
-    return -1;
-  if (result == -1)
-    chars_avail = 0;
-#endif
-
-  if (result == -1 && rl_input_available_hook)
+  /* Move this up here to give it first shot, but it can't set chars_avail */
+  /* XXX - need rl_chars_available_hook? */
+  if (rl_input_available_hook)
     {
       result = (*rl_input_available_hook) ();
       if (result == 0)
         result = -1;
     }
 
+#if defined (HAVE_PSELECT) || defined (HAVE_SELECT)
+  if (result == -1)
+    {
+      FD_ZERO (&readfds);
+      FD_ZERO (&exceptfds);
+      FD_SET (tty, &readfds);
+      FD_SET (tty, &exceptfds);
+      USEC_TO_TIMEVAL (_keyboard_input_timeout, timeout);
+#if defined (RL_TIMEOUT_USE_SELECT)
+      result = _rl_timeout_select (tty + 1, &readfds, (fd_set *)NULL, &exceptfds, &timeout, NULL);
+#else
+      result = select (tty + 1, &readfds, (fd_set *)NULL, &exceptfds, &timeout);
+#endif
+      if (result <= 0)
+	return 0;	/* Nothing to read. */
+    }
+#endif
+
+#if defined (FIONREAD)
+  if (result == -1)
+    {
+      errno = 0;
+      result = ioctl (tty, FIONREAD, &chars_avail);
+      if (result == -1 && errno == EIO)
+	return -1;
+      if (result == -1)
+	chars_avail = 0;
+    }
+#endif
+
 #if defined (O_NDELAY)
   if (result == -1)
     {
@@ -315,8 +316,11 @@ rl_gather_tyi (void)
 #if defined (__MINGW32__)
   /* Use getch/_kbhit to check for available console input, in the same way
      that we read it normally. */
-   chars_avail = isatty (tty) ? _kbhit () : 0;
-   result = 0;
+   if (result == -1)
+     {
+       chars_avail = isatty (tty) ? _kbhit () : 0;
+       result = 0;
+     }
 #endif
 
   /* If there's nothing available, don't waste time trying to read
@@ -658,7 +662,7 @@ rl_timeout_remaining (unsigned int *secs, unsigned int *usecs)
 
 /* This should only be called if RL_TIMEOUT_USE_SELECT is defined. */
 
-#if defined (HAVE_PSELECT) || defined (HAVE_SELECT)
+#if defined (RL_TIMEOUT_USE_SELECT)
 int
 _rl_timeout_select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timeval *timeout, const sigset_t *sigmask)
 {

lib/readline/rlprivate.h

@@ -303,8 +303,22 @@ extern int _rl_pushed_input_available (void);
 
 extern int _rl_timeout_init (void);
 extern int _rl_timeout_handle_sigalrm (void);
-#if defined (_POSIXSELECT_H_) && !defined (__MINGW32__) && (defined (HAVE_SELECT) || defined (HAVE_PSELECT))
+
+#if defined (_POSIXSELECT_H_)
 /* use as a sentinel for fd_set, struct timeval,  and sigset_t definitions */
+
+#if defined (__MINGW32__)
+#  define RL_TIMEOUT_USE_SIGALRM
+#elif defined (HAVE_SELECT) || defined (HAVE_PSELECT)
+#  define RL_TIMEOUT_USE_SELECT
+#elif defined (_MSC_VER)
+/* can't use select/pselect or SIGALRM, so no timeouts */
+#else
+#  define RL_TIMEOUT_USE_SIGALRM
+#endif
+
+#endif
+#if defined (RL_TIMEOUT_USE_SELECT)
 extern int _rl_timeout_select (int, fd_set *, fd_set *, fd_set *, const struct timeval *, const sigset_t *);
 #endif
 

subst.c

@@ -3461,7 +3461,7 @@ do_assignment_internal (const WORD_DESC *word, int expand)
   char *t;
   int ni;
 #endif
-  const char *string;
+  char *string;
 
   if (word == 0 || word->word == 0)
     return 0;
@@ -3469,7 +3469,7 @@ do_assignment_internal (const WORD_DESC *word, int expand)
   appendop = assign_list = aflags = 0;
   string = word->word;
   offset = assignment (string, 0);
-  name = savestring (string);
+  name = string;
   value = (char *)NULL;
 
   if (name[offset] == '=')
@@ -3512,12 +3512,20 @@ do_assignment_internal (const WORD_DESC *word, int expand)
 	name[offset - 1] = '\0';
     }
 
-#define ASSIGN_RETURN(r)	do { FREE (value); free (name); return (r); } while (0)
+#define ASSIGN_RETURN(r) \
+do \
+{ \
+  FREE (value); \
+  if (appendop) name[offset - 1] = '+'; \
+  name[offset] = '='; \
+  return (r); \
+} while (0)
 
   if (appendop)
     aflags |= ASS_APPEND;
 
 #if defined (ARRAY_VARS)
+  /* could use strchr, since variable names can't yet contain multibyte characters */
   if (t = mbschr (name, LBRACK))
     {
       if (assign_list)

trap.c

@@ -902,6 +902,17 @@ restore_default_signal (int sig)
   if (sigmodes[sig] & SIG_HARD_IGNORE)
     return;
 
+  /* Even if the signal is not trapped, POSIX interp 751 requires that we
+     allow `trap - SIGINT' to reset the signal disposition for SIGINT to
+     SIG_DFL. */
+  if ((sigmodes[sig] & (SIG_TRAPPED|SIG_ASYNCSIG|SIG_NO_TRAP)) == SIG_ASYNCSIG)
+    {
+      original_signals[sig] = SIG_DFL;	/* XXX */
+      set_signal_handler (sig, SIG_DFL);
+      change_signal (sig, (char *)DEFAULT_SIG);
+      return;
+    }
+    
   /* If we aren't trapping this signal, don't bother doing anything else. */
   /* We special-case SIGCHLD and IMPOSSIBLE_TRAP_HANDLER (see above) as a
      sentinel to determine whether or not disposition is reset to the default