1 files changed, 8 insertions, 2 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 3407711cd..c4b124825 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1683,9 +1683,15 @@ static void close_all_HFILE_list(void)
                  * It is disastrous if we share memory with a vforked parent.
                  * I'm not sure we never come here after vfork.
                  * Therefore just close fd, nothing more.
+                 *
+                 * ">" instead of ">=": we don't close fd#0,
+                 * interactive shell uses hfopen(NULL) as stdin input
+                 * which has fl->fd == 0, but fd#0 gets redirected in pipes.
+                 * If we'd close it here, then e.g. interactive "set | sort"
+                 * with NOFORKed sort, would have sort's input fd closed.
                  */
-                /*hfclose(fl); - unsafe */
-                if (fl->fd >= 0)
+                if (fl->fd > 0)
+                        /*hfclose(fl); - unsafe */
                         close(fl->fd);
                 fl = fl->next_hfile;
         }