1 files changed, 22 insertions, 7 deletions

diff --git a/bin/sh/redir.c b/bin/sh/redir.c
index 95d3238..0a7aa96 100644
--- a/bin/sh/redir.c
+++ b/bin/sh/redir.c
@@ -70,6 +70,7 @@ struct redirtab {
 	struct redirtab *next;
 	int renamed[10];
 	int fd0_redirected;
+	unsigned int empty_redirs;
 };
 
 
@@ -82,6 +83,9 @@ static struct redirtab *redirlist;
 */
 static int fd0_redirected = 0;
 
+/* Number of redirtabs that have not been allocated. */
+static unsigned int empty_redirs = 0;
+
 static void openredirect(union node *, char[10 ]);
 static int openhere(union node *);
 
@@ -115,12 +119,17 @@ redirect(union node *redir, int flags)
 		memory[i] = 0;
 	memory[1] = flags & REDIR_BACKQ;
 	if (flags & REDIR_PUSH) {
-		sv = ckmalloc(sizeof (struct redirtab));
-		for (i = 0 ; i < 10 ; i++)
-			sv->renamed[i] = EMPTY;
-		sv->fd0_redirected = fd0_redirected;
-		sv->next = redirlist;
-		redirlist = sv;
+		empty_redirs++;
+		if (redir != NULL) {
+			sv = ckmalloc(sizeof (struct redirtab));
+			for (i = 0 ; i < 10 ; i++)
+				sv->renamed[i] = EMPTY;
+			sv->fd0_redirected = fd0_redirected;
+			sv->empty_redirs = empty_redirs - 1;
+			sv->next = redirlist;
+			redirlist = sv;
+			empty_redirs = 0;
+		}
 	}
 	for (n = redir ; n ; n = n->nfile.next) {
 		fd = n->nfile.fd;
@@ -303,6 +312,12 @@ popredir(void)
 	struct redirtab *rp = redirlist;
 	int i;
 
+	INTOFF;
+	if (empty_redirs > 0) {
+		empty_redirs--;
+		INTON;
+		return;
+	}
 	for (i = 0 ; i < 10 ; i++) {
 		if (rp->renamed[i] != EMPTY) {
 			if (rp->renamed[i] >= 0) {
@@ -313,8 +328,8 @@ popredir(void)
 			}
 		}
 	}
-	INTOFF;
 	fd0_redirected = rp->fd0_redirected;
+	empty_redirs = rp->empty_redirs;
 	redirlist = rp->next;
 	ckfree(rp);
 	INTON;