trap: Allow INT to be an alias for SIGINT.

bash and mksh accept both SIGINT and INT; dash only allows INT.

core/builtin.py

@@ -57,7 +57,7 @@
CD PUSHD POPD DIRS
EXPORT UNSET SET SHOPT
TRAP UMASK
EXIT SOURCE DOT EVAL EXEC WAIT JOBS 
EXIT SOURCE DOT EVAL EXEC WAIT JOBS
COMPLETE COMPGEN DEBUG_LINE
TRUE FALSE
COLON
@@ -1017,10 +1017,18 @@ def _MakeSignals():
    # don't want SIG_DFL or SIG_IGN
    if name.startswith('SIG') and not name.startswith('SIG_'):
      int_val = getattr(signal, name)
      names[name] = int_val
      abbrev = name[3:]
      names[abbrev] = int_val
  return names


def _GetSignalValue(sig_spec):
  # INT is an alias for SIGINT
  if sig_spec.startswith('SIG'):
    sig_spec = sig_spec[3:]
  return _SIGNAL_NAMES.get(sig_spec)


_SIGNAL_NAMES = _MakeSignals()

_HOOK_NAMES = ('EXIT', 'ERR', 'RETURN', 'DEBUG')
@@ -1037,7 +1045,7 @@ def _MakeSignals():
# trap -- '' SIGTTIN
# trap -- '' SIGTTOU
#
# CPython registers different default handlers.  Wait until C++ rewrite to 
# CPython registers different default handlers.  Wait until C++ rewrite to

def Trap(argv, traps, ex):
  arg, i = TRAP_SPEC.Parse(argv)
@@ -1058,7 +1066,7 @@ def Trap(argv, traps, ex):
    for name in _HOOK_NAMES:
      print('   %s' % name)
    for name, int_val in ordered:
      print('%02d %s' % (int_val, name))
      print('%2d %s' % (int_val, name))

    sys.stdout.flush()
    return 0
@@ -1079,7 +1087,7 @@ def Trap(argv, traps, ex):
        pass
      return 0

    sig_val = _SIGNAL_NAMES.get(sig_spec)
    sig_val = _GetSignalValue(sig_spec)
    if sig_val is not None:
      try:
        del traps[sig_spec]
@@ -1106,7 +1114,7 @@ def Trap(argv, traps, ex):
    return 0

  # Register a signal.
  sig_val = _SIGNAL_NAMES.get(sig_spec)
  sig_val = _GetSignalValue(sig_spec)
  if sig_val is not None:
    handler = _TrapThunk(ex, node)
    # For signal handlers, the traps dictionary is used only for debugging.

spec/builtin-trap.test.sh

@@ -1,7 +1,7 @@
#!/bin/bash

### trap -l
trap -l | grep SIGINT >/dev/null
trap -l | grep INT >/dev/null
## status: 0
## N-I dash/mksh status: 1

@@ -19,6 +19,20 @@ trap 'foo' SIGINVALID
trap - SIGINVALID
## status: 1

### SIGINT and INT are aliases
trap - SIGINT
echo $?
trap - INT
echo $?
## STDOUT:
0
0
## END
## N-I dash STDOUT:
1
0
## END

### Invalid trap invocation
trap 'foo'
echo status=$?