Issue yuin#452 : fix xpcall with error in error handler returns (nil,…

… nil)

_glua-tests/issues.lua

@@ -457,3 +457,14 @@ function test()
   assert(c == 1)
   assert(type(c) == "number")
 end
+
+-- issue #452
+function test()
+  local ok, msg = pcall(function()
+    local ok, msg = xpcall(function() error("fn") end, function(err) error("handler") end)
+    assert(not ok and msg)
+    error("expected to reach this.")
+  end)
+  assert(not ok)
+end
+test()

_state.go

@@ -1855,6 +1855,9 @@ func (ls *LState) PCall(nargs, nret int, errfunc *LFunction) (err error) {
 							err = rcv.(*ApiError)
 							err.(*ApiError).StackTrace = ls.stackTrace(0)
 						}
+						ls.stack.SetSp(sp)
+						ls.currentFrame = ls.stack.Last()
+						ls.reg.SetTop(base)
 					}
 				}()
 				ls.Call(1, 1)

state.go

@@ -2014,6 +2014,9 @@ func (ls *LState) PCall(nargs, nret int, errfunc *LFunction) (err error) {
 							err = rcv.(*ApiError)
 							err.(*ApiError).StackTrace = ls.stackTrace(0)
 						}
+						ls.stack.SetSp(sp)
+						ls.currentFrame = ls.stack.Last()
+						ls.reg.SetTop(base)
 					}
 				}()
 				ls.Call(1, 1)

state_test.go

@@ -291,17 +291,39 @@ func TestPCall(t *testing.T) {
 	}))
 	errorIfFalse(t, strings.Contains(err.Error(), "by handler"), "")
 
+	L.Push(L.GetGlobal("f1"))
 	err = L.PCall(0, 0, L.NewFunction(func(L *LState) int {
 		L.RaiseError("error!")
 		return 1
 	}))
 	errorIfFalse(t, strings.Contains(err.Error(), "error!"), "")
 
+	L.Push(L.GetGlobal("f1"))
 	err = L.PCall(0, 0, L.NewFunction(func(L *LState) int {
 		panic("panicc!")
 		return 1
 	}))
 	errorIfFalse(t, strings.Contains(err.Error(), "panicc!"), "")
+
+	// Issue #452, expected to be revert back to previous call stack after any error.
+	currentFrame, currentTop, currentSp := L.currentFrame, L.GetTop(), L.stack.Sp()
+	L.Push(L.GetGlobal("f1"))
+	err = L.PCall(0, 0, nil)
+	errorIfFalse(t, err != nil, "")
+	errorIfFalse(t, L.currentFrame == currentFrame, "")
+	errorIfFalse(t, L.GetTop() == currentTop, "")
+	errorIfFalse(t, L.stack.Sp() == currentSp, "")
+
+	currentFrame, currentTop, currentSp = L.currentFrame, L.GetTop(), L.stack.Sp()
+	L.Push(L.GetGlobal("f1"))
+	err = L.PCall(0, 0, L.NewFunction(func(L *LState) int {
+		L.RaiseError("error!")
+		return 1
+	}))
+	errorIfFalse(t, err != nil, "")
+	errorIfFalse(t, L.currentFrame == currentFrame, "")
+	errorIfFalse(t, L.GetTop() == currentTop, "")
+	errorIfFalse(t, L.stack.Sp() == currentSp, "")
 }
 
 func TestCoroutineApi1(t *testing.T) {