ash: fix $! value when traps are set

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

6 files changed, 41 insertions, 2 deletions

diff --git a/shell/ash.c b/shell/ash.c
index fd119fa51..988edab8a 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -4633,6 +4633,7 @@ clear_traps(void)
 			INT_ON;
 		}
 	}
+	may_have_traps = 0;
 }
 
 /* Lives far away from here, needed for forkchild */
diff --git a/shell/ash_test/ash-signals/signal7.right b/shell/ash_test/ash-signals/signal7.right
new file mode 100644
index 000000000..ba7453e42
--- /dev/null
+++ b/shell/ash_test/ash-signals/signal7.right
@@ -0,0 +1 @@
+Bug detected: 0
diff --git a/shell/ash_test/ash-signals/signal7.tests b/shell/ash_test/ash-signals/signal7.tests
new file mode 100755
index 000000000..c2b1381f9
--- /dev/null
+++ b/shell/ash_test/ash-signals/signal7.tests
@@ -0,0 +1,18 @@
+bug() {
+	trap : exit
+	# Bug was causing sh to be run in subshell,
+	# as if this line is replaced with (sh -c ...; exit $?) &
+	# here:
+	sh -c 'echo REAL_CHILD=$$' &
+	echo PARENTS_IDEA_OF_CHILD=$!
+	wait  # make sure bkgd shell completes
+}
+
+bug | {
+while read varval; do
+	eval $varval
+done
+test x"$REAL_CHILD" != x"" \
+&& test x"$REAL_CHILD" = x"$PARENTS_IDEA_OF_CHILD"
+echo "Bug detected: $?"
+}
diff --git a/shell/hush.c b/shell/hush.c
index 9208ec497..45c98bb36 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4108,8 +4108,6 @@ static void insert_bg_job(struct pipe *pi)
 
 	if (G_interactive_fd)
 		printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
-	/* Last command's pid goes to $! */
-	G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
 	G.last_jobid = job->jobid;
 }
 
@@ -5076,6 +5074,8 @@ static int run_list(struct pipe *pi)
 				if (G.run_list_level == 1)
 					insert_bg_job(pi);
 #endif
+				/* Last command's pid goes to $! */
+				G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
 				G.last_exitcode = rcode = EXIT_SUCCESS;
 				debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
 			} else {
diff --git a/shell/hush_test/hush-trap/signal7.right b/shell/hush_test/hush-trap/signal7.right
new file mode 100644
index 000000000..ba7453e42
--- /dev/null
+++ b/shell/hush_test/hush-trap/signal7.right
@@ -0,0 +1 @@
+Bug detected: 0
diff --git a/shell/hush_test/hush-trap/signal7.tests b/shell/hush_test/hush-trap/signal7.tests
new file mode 100755
index 000000000..c2b1381f9
--- /dev/null
+++ b/shell/hush_test/hush-trap/signal7.tests
@@ -0,0 +1,18 @@
+bug() {
+	trap : exit
+	# Bug was causing sh to be run in subshell,
+	# as if this line is replaced with (sh -c ...; exit $?) &
+	# here:
+	sh -c 'echo REAL_CHILD=$$' &
+	echo PARENTS_IDEA_OF_CHILD=$!
+	wait  # make sure bkgd shell completes
+}
+
+bug | {
+while read varval; do
+	eval $varval
+done
+test x"$REAL_CHILD" != x"" \
+&& test x"$REAL_CHILD" = x"$PARENTS_IDEA_OF_CHILD"
+echo "Bug detected: $?"
+}