Handle the case where we have a bracketed expression with redirection.

In this case, make sure we fork and we do io processing.

if ( { ping -c 1 192.168.3.9 >& /dev/null } ) then
  echo "LAN is up"
endif

Fixes

@@ -1,3 +1,5 @@
+ 39. Handle redirections in bracketed expressions if { foo > /dev/null }
+     (christos)
  38. Recognize history searches in history expansion !?foo<tab> (christos)
  37. V6.24.13 - 2024-06-12
  36. Fix !^:h and !^:t failing when no / found (Kimmo Suominen)

sh.exp.c

@@ -966,6 +966,8 @@ evalav(Char **v)
     cleanup_push(&paraml1, lex_cleanup);
     alias(&paraml1);
     t = syntax(paraml1.next, &paraml1, 0);
+    if (t->t_dflg & F_REDIR)
+	t->t_dflg |= F_FORK;
     cleanup_push(t, syntax_cleanup);
     if (seterr)
 	stderror(ERR_OLD);

sh.h

@@ -918,6 +918,8 @@ struct command {
 #ifdef apollo
 #define F_VER		(1<<16)	/* execute command under SYSTYPE */
 #endif
+#define F_FORK		(1<<17)	/* force forking		*/
+#define F_REDIR		(1<<18)	/* output redirected		*/
     union {
 	Char   *T_dlef;		/* Input redirect word 		 */
 	struct command *T_dcar;	/* Left part of list/pipe 	 */

sh.parse.c

@@ -567,6 +567,7 @@ syn3(const struct wordent *p1, const struct wordent *p2, int flags)
 	    goto savep;
 
 	case '>':
+	    t->t_dflg |= F_REDIR;
 	    if (l != 0)
 		goto savep;
 	    if (p->word[1] == '>')

sh.sem.c

@@ -376,7 +376,7 @@ execute(struct command *t, volatile int wanttty, int *pipein, int *pipeout,
 		       bifunc->bfunct == (bfunc_t)dopopd))
 	    t->t_dflg &= ~(F_NICE);
 
-	if (((t->t_dflg & F_TIME) || ((t->t_dflg & F_NOFORK) == 0 &&
+	if (((t->t_dflg & F_TIME|F_FORK) || ((t->t_dflg & F_NOFORK) == 0 &&
 	     (!bifunc || t->t_dflg &
 	      (F_PIPEOUT | F_AMPERSAND | F_NICE | F_NOHUP | F_HUP)))) ||
 	/*
@@ -843,8 +843,7 @@ doio(struct command *t, int *pipein, int *pipeout)
     int fd;
     Char *cp;
     unsigned long flags = t->t_dflg;
-
-    if (didfds || (flags & F_REPEAT))
+    if ((flags & F_FORK) == 0 && (didfds || (flags & F_REPEAT)))
 	return;
     if ((flags & F_READ) == 0) {/* F_READ already done */
 	if (t->t_dlef) {