[test/stateful] Test case for running handlers at prompt.

This is a reproduction of #1080.

spec/stateful/signals.py

@@ -9,7 +9,7 @@
 import time
 
 import harness
-from harness import register
+from harness import register, expect_prompt
 
 
 #
@@ -67,19 +67,37 @@
 #    3. trap 'echo X' SIGINT ?
 
 
+@register()
+def sigusr1_trapped_prompt(sh):
+  'Trapped SIGUSR1 while waiting at prompt (bug 1080)'
+  expect_prompt(sh)
+
+  sh.sendline("trap 'echo zzz-USR1' USR1")
+  expect_prompt(sh)
+
+  sh.kill(signal.SIGUSR1)
+
+  # bash and dash need another blank line, mksh doesn't
+  sh.sendline('')
+
+  sh.expect('zzz-USR1')
+
+
 @register()
 def sighup_trapped_wait(sh):
   'trapped SIGHUP during wait builtin'
 
   sh.sendline("trap 'echo HUP' HUP")
+  expect_prompt(sh)
   sh.sendline('sleep 1 &')
+  # TODO: expect something like [1] 24370
   sh.sendline('wait')
 
   time.sleep(0.1)
 
   sh.kill(signal.SIGHUP)
 
-  sh.expect(r'.*\$')  # expect prompt
+  expect_prompt(sh)
 
   sh.sendline('echo status=$?')
   sh.expect('status=129')

test/stateful.sh

@@ -37,7 +37,7 @@ run() {
 readonly FIRST=''
 
 signals-quick() {
-  spec/stateful/signals.py $FIRST \
+  spec/stateful/signals.py $FIRST --osh-failures-allowed 1 \
     $OSH bash "$@"
 }