change behaviour of argument-less exit in traps to match SUSv4; Debian #599484 (original patch from Jonathan Nieder, thanks!) in a variant that appears to handle nested traps well

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.395 2010/10/01 19:04:37 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.396 2010/11/01 17:29:00 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -25,7 +25,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R39 2010/10/01
+	@(#)MIRBSD KSH R39 2010/11/01
 description:
 	Check version of shell.
 stdin:
@@ -4845,6 +4845,16 @@ expected-stdout:
 	E 0
 	F 0
 ---
+name: exit-trap-1
+description:
+	Check that "exit" with no arguments behaves SUSv4 conformant.
+stdin:
+	trap 'echo hi; exit' EXIT
+	exit 9
+expected-stdout:
+	hi
+expected-exit: 9
+---
 name: test-stlt-1
 description:
 	Check that test also can handle string1 < string2 etc.

funcs.c

@@ -25,7 +25,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.163 2010/09/15 21:08:18 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.164 2010/11/01 17:29:02 tg Exp $");
 
 #if HAVE_KILLPG
 /*
@@ -2293,7 +2293,8 @@ c_exitreturn(const char **wp)
 			warningf(true, "%s: %s", arg, "bad number");
 		} else
 			exstat = n;
-	}
+	} else if (trap_exstat != -1)
+		exstat = trap_exstat;
 	if (wp[0][0] == 'r') { /* return */
 		struct env *ep;
 

histrap.c

@@ -26,7 +26,7 @@
 #include <sys/file.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.102 2010/09/14 21:26:13 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.103 2010/11/01 17:29:03 tg Exp $");
 
 /*-
  * MirOS: This is the default mapping type, and need not be specified.
@@ -1066,6 +1066,8 @@ inittraps(void)
 	int i;
 	const char *cs;
 
+	trap_exstat = -1;
+
 	/* Populate sigtraps based on sys_signame and sys_siglist. */
 	for (i = 0; i <= NSIG; i++) {
 		sigtraps[i].signal = i;
@@ -1271,22 +1273,29 @@ runtraps(int flag)
 		intrsig = 0;
 	if (flag & TF_FATAL)
 		fatal_trap = 0;
+	++trap_nested;
 	for (p = sigtraps, i = NSIG+1; --i >= 0; p++)
 		if (p->set && (!flag ||
 		    ((p->flags & flag) && p->trap == NULL)))
-			runtrap(p);
+			runtrap(p, false);
+	if (!--trap_nested)
+		runtrap(NULL, true);
 }
 
 void
-runtrap(Trap *p)
+runtrap(Trap *p, bool is_last)
 {
-	int	i = p->signal;
+	int old_changed = 0, i;
-	char	*trapstr = p->trap;
+	char *trapstr;
-	int	oexstat;
-	int	old_changed = 0;
 
+	if (p == NULL)
+		/* just clean up, see runtraps() above */
+		goto donetrap;
+	i = p->signal;
+	trapstr = p->trap;
 	p->set = 0;
-	if (trapstr == NULL) { /* SIG_DFL */
+	if (trapstr == NULL) {
+		/* SIG_DFL */
 		if (p->flags & TF_FATAL) {
 			/* eg, SIGHUP */
 			exstat = 128 + i;
@@ -1297,22 +1306,23 @@ runtrap(Trap *p)
 			exstat = 128 + i;
 			unwind(LINTR);
 		}
-		return;
+		goto donetrap;
 	}
-	if (trapstr[0] == '\0') /* SIG_IGN */
+	if (trapstr[0] == '\0')
-		return;
+		/* SIG_IGN */
+		goto donetrap;
 	if (i == SIGEXIT_ || i == SIGERR_) {	/* avoid recursion on these */
 		old_changed = p->flags & TF_CHANGED;
 		p->flags &= ~TF_CHANGED;
 		p->trap = NULL;
 	}
-	oexstat = exstat;
+	if (trap_exstat == -1)
+		trap_exstat = exstat;
 	/*
 	 * Note: trapstr is fully parsed before anything is executed, thus
 	 * no problem with afree(p->trap) in settrap() while still in use.
 	 */
 	command(trapstr, current_lineno);
-	exstat = oexstat;
 	if (i == SIGEXIT_ || i == SIGERR_) {
 		if (p->flags & TF_CHANGED)
 			/* don't clear TF_CHANGED */
@@ -1321,6 +1331,13 @@ runtrap(Trap *p)
 			p->trap = trapstr;
 		p->flags |= old_changed;
 	}
+
+ donetrap:
+	/* we're the last trap of a sequence executed */
+	if (is_last && trap_exstat != -1) {
+		exstat = trap_exstat;
+		trap_exstat = -1;
+	}
 }
 
 /* clear pending traps and reset user's trap handlers; used after fork(2) */

main.c

@@ -33,7 +33,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.172 2010/09/14 21:26:14 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.173 2010/11/01 17:29:04 tg Exp $");
 
 extern char **environ;
 
@@ -672,10 +672,14 @@ unwind(int i)
 	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR) &&
 	    sigtraps[SIGEXIT_].trap)) {
-		runtrap(&sigtraps[SIGEXIT_]);
+		++trap_nested;
+		runtrap(&sigtraps[SIGEXIT_], trap_nested == 1);
+		--trap_nested;
 		i = LLEAVE;
 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
-		runtrap(&sigtraps[SIGERR_]);
+		++trap_nested;
+		runtrap(&sigtraps[SIGERR_], trap_nested == 1);
+		--trap_nested;
 		i = LLEAVE;
 	}
 	while (1) {

sh.h

@@ -154,9 +154,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.418 2010/10/08 17:56:57 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.419 2010/11/01 17:29:05 tg Exp $");
 #endif
-#define MKSH_VERSION "R39 2010/10/01"
+#define MKSH_VERSION "R39 2010/11/01"
 
 #ifndef MKSH_INCLUDES_ONLY
 
@@ -584,6 +584,8 @@ EXTERN struct mksh_kshstate_v {
 	int exstat_;		/* exit status */
 	int subst_exstat_;	/* exit status of last $(..)/`..` */
 	struct env env_;	/* top-level parsing & execution env. */
+	short trap_exstat_;	/* exit status before running a trap */
+	uint8_t trap_nested_;	/* running nested traps */
 	uint8_t shell_flags_[FNFLAGS];
 } kshstate_v;
 EXTERN struct mksh_kshstate_f {
@@ -602,6 +604,8 @@ EXTERN struct mksh_kshstate_f {
 #define kshppid		kshstate_f.kshppid_
 #define exstat		kshstate_v.exstat_
 #define subst_exstat	kshstate_v.subst_exstat_
+#define trap_exstat	kshstate_v.trap_exstat_
+#define trap_nested	kshstate_v.trap_nested_
 
 /* evil hack: return hash(kshstate_f concat (kshstate_f'.h:=hash(arg))) */
 uint32_t evilhash(const char *);
@@ -1526,7 +1530,7 @@ void intrcheck(void);
 int fatal_trap_check(void);
 int trap_pending(void);
 void runtraps(int intr);
-void runtrap(Trap *);
+void runtrap(Trap *, bool);
 void cleartraps(void);
 void restoresigs(void);
 void settrap(Trap *, const char *);