bug fix

Author: tangzx

src/main/java/com/tang/intellij/lua/stubs/LuaFuncBodyOwnerStub.kt

@@ -57,7 +57,7 @@ interface LuaFuncBodyOwnerStub<T : LuaFuncBodyOwner> : StubElement<T> {
     fun guessReturnTy(context: SearchContext): ITy {
         val docTy = returnDocTy
         if (docTy != null){
-            if (docTy is TyTuple) {
+            if (docTy is TyTuple && context.index != -1) {
                 return docTy.list.getOrElse(context.index) { Ty.UNKNOWN }
             }
             return docTy

src/main/java/com/tang/intellij/lua/ty/TyFunction.kt

@@ -260,7 +260,7 @@ class TyPsiFunction(private val selfCall: Boolean, val psi: LuaFuncBodyOwner, se
 
         object : FunSignatureBase(selfCall, psi.params) {
             override val returnTy: ITy by lazy {
-                var returnTy = psi.guessReturnType(searchContext)
+                var returnTy = psi.guessReturnType(SearchContext(psi.project))
                 /**
                  * todo optimize this bug solution
                  * local function test()