hush: fix "cmd & <newline>" problem

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 5 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 6970c50c4..3581ba119 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4141,15 +4141,26 @@ static struct pipe *parse_stream(char **pstring,
                                  && dest.length == 0 && !dest.has_quoted_part
                                 ) {
                                         /* This newline can be ignored. But...
-                                         * without the below check, interactive shell
-                                         * will ignore even lines with bare <newline>,
-                                         * and show the continuation prompt:
+                                         * Without check #1, interactive shell
+                                         * ignores even bare <newline>,
+                                         * and shows the continuation prompt:
                                          * ps1_prompt$ <enter>
-                                         * ps2> _   <=== wrong prompt, should be ps1
+                                         * ps2> _   <=== wrong, should be ps1
+                                         * Without check #2, "cmd & <newline>"
+                                         * is similarly mistreated.
+                                         * (BTW, this makes "cmd & cmd"
+                                         * and "cmd && cmd" non-orthogonal.
+                                         * Really, ask yourself, why
+                                         * "cmd && <newline>" doesn't start
+                                         * cmd but waits for more input?
+                                         * No reason...)
                                          */
                                         struct pipe *pi = ctx.list_head;
-                                        if (pi->num_cmds != 0)
+                                        if (pi->num_cmds != 0       /* check #1 */
+                                         && pi->followup != PIPE_BG /* check #2 */
+                                        ) {
                                                 continue;
+                                        }
                                 }
                                 /* Treat newline as a command separator. */
                                 done_pipe(&ctx, PIPE_SEQ);