Fix go n steps in pipe (#326)

Co-authored-by: Yee <2520865+yixinglu@users.noreply.github.com>

src/validator/TraversalValidator.cpp

@@ -148,7 +148,7 @@ PlanNode* TraversalValidator::projectDstVidsFromGN(PlanNode* gn, const std::stri
     columns->addColumn(column);
 
     srcVidColName_ = vctx_->anonColGen()->getCol();
-    if (!exprProps_.inputProps().empty() || !exprProps_.varProps().empty()) {
+    if (from_.fromType != FromType::kInstantExpr) {
         column =
             new YieldColumn(new InputPropertyExpression(new std::string(kVid)),
                             new std::string(srcVidColName_));

tests/query/v1/test_go.py

@@ -963,12 +963,17 @@ class TestGoQuery(NebulaTestSuite):
         expected_data = {
             "column_names" : ["like._dst"],
             "rows" : [
-                ["Tony Parker"],
+                ["LaMarcus Aldridge"],
+                ["LaMarcus Aldridge"],
                 ["Manu Ginobili"],
                 ["Manu Ginobili"],
                 ["Tim Duncan"],
                 ["Tim Duncan"],
-                ["LaMarcus Aldridge"],
+                ["Tim Duncan"],
+                ["Manu Ginobili"],
+                ["Manu Ginobili"],
+                ["Tony Parker"],
+                ["Tony Parker"],
             ]
         }
         self.check_column_names(resp, expected_data["column_names"])