Bug fix for debug.sethook (passing on errors)

[Stefan Reich]

Hi!

I think I have fixed a bug in LuaJ. Or, let's say, a difference in behavior compared to C-Lua. If you call error() in a debug hook, the error is not passed on to the coroutine as it should.

Fix (org/luaj/vm2/lib/DebugLib.java, replace the whole function):

void callHook(LuaValue type, LuaValue arg) {
    LuaThread t = globals.running;
    t.inhook = true;
    try {
        t.hookfunc.call(type, arg);
// XXX (Stefan) - following two lines commented out should fix timeout bug (using debug.hook for timeouts)
    /*} catch (Exception e) {
        e.printStackTrace();*/
    } finally {
        t.inhook = false;
    }
}

After fixing this, debug hooks can be used to cancel too long-running Lua calculations. (Very important if you need proper, i.e. tight, sandboxing.)

I'm waiting for Jim to confirm that this bug fix is OK.

Cheers,
Stefan Reich
(TinyBrain.de)