Fixed issue: #86

core/src/main/java/org/luaj/vm2/libs/DebugLib.java

@@ -173,10 +173,16 @@ public class DebugLib extends TwoArgFunction {
 			// find the stack info
 			DebugLib.CallFrame frame;
 			if ( func.isnumber() ) {
-				frame = callstack.getCallFrame(func.toint());
-				if (frame == null)
-					return NONE;
-				func = frame.f;
+				int level = func.toint();
+				if (level == 0) {
+					frame = null;
+					func = this;
+				} else {
+					frame = callstack.getCallFrame(level);
+					if (frame == null)
+						return NONE;
+					func = frame.f;
+				}
 			} else if ( func.isfunction() ) {
 				frame = callstack.findCallFrame(func);
 			} else {
@@ -453,12 +459,14 @@ public class DebugLib extends TwoArgFunction {
 		if (s.inhook || s.hookfunc == null) return;
 		s.inhook = true;
 		try {
+			callstack().onCall(s.hookfunc.checkfunction());
 			s.hookfunc.call(type, arg);
 		} catch (LuaError e) {
 			throw e;
 		} catch (RuntimeException e) {
 			throw new LuaError(e);
 		} finally {
+			callstack().onReturn();
 			s.inhook = false;
 		}
 	}