Workaround for vesoft-inc#2087, which lose the data when join with du…

…plicate in… (vesoft-inc#2089)

* Workaround for vesoft-inc#2087, which lose the data when join with duplicate input(VID)

* Remove the useless comment.

* Add some cases.

* For variable input also.

Co-authored-by: dutor <440396+dutor@users.noreply.github.com>

src/graph/GoExecutor.cpp

@@ -495,6 +495,14 @@ Status GoExecutor::setupStarts() {
         return std::move(result).status();
     }
     starts_ = std::move(result).value();
+    std::unordered_set<VertexID> uni;
+    uni.reserve(starts_.size());
+    uni.insert(starts_.begin(), starts_.end());
+    if (starts_.size() == uni.size()) {
+        uniqueStart_ = true;
+    } else {
+        uniqueStart_ = false;
+    }
 
     auto indexResult = inputs->buildIndex(*colname_);
     if (!indexResult.ok()) {
@@ -1142,11 +1150,18 @@ bool GoExecutor::processFinalResult(RpcResponse &rpcResp, Callback cb) const {
                         return ret.value();
                     };
                     getters.getVariableProp = [&srcId,
-                                               this] (const std::string &prop) {
+                                               this] (const std::string &prop) -> OptVariantType {
+                        if (!uniqueStart_) {
+                            return Status::NotSupported(
+                                "Not supported duplicate start from variable");
+                        }
                         return getPropFromInterim(srcId, prop);
                     };
                     getters.getInputProp = [&srcId,
-                                            this] (const std::string &prop) {
+                                            this] (const std::string &prop) -> OptVariantType {
+                        if (!uniqueStart_) {
+                            return Status::NotSupported("Not supported duplicate start from input");
+                        }
                         return getPropFromInterim(srcId, prop);
                     };
 

src/graph/GoExecutor.h

@@ -226,6 +226,8 @@ class GoExecutor final : public TraverseExecutor {
     std::unique_ptr<VertexHolder>               vertexHolder_;
     std::unique_ptr<VertexBackTracker>          backTracker_;
     std::unique_ptr<cpp2::ExecutionResponse>    resp_;
+    // TODO(shylock) Join lose the data with duplicate input(VID) map
+    bool                                        uniqueStart_{false};  // #2087 Workaround
     // The name of Tag or Edge, index of prop in data
     using SchemaPropIndex = std::unordered_map<std::pair<std::string, std::string>, int64_t>;
 };

src/graph/test/GoTest.cpp

@@ -2369,6 +2369,27 @@ TEST_P(GoTest, Contains) {
     }
 }
 
+TEST_P(GoTest, issue2087) {
+    // from input
+    {
+        cpp2::ExecutionResponse resp;
+        auto *fmt = "GO FROM %ld OVER like YIELD like._src as src, like._dst as dst "
+            "| GO FROM $-.src OVER like YIELD $-.src as src, like._dst as dst";
+        auto query = folly::stringPrintf(fmt, players_["Tim Duncan"].vid());
+        auto code = client_->execute(query, resp);
+        ASSERT_EQ(cpp2::ErrorCode::E_EXECUTION_ERROR, code);
+    }
+    // from variable
+    {
+        cpp2::ExecutionResponse resp;
+        auto *fmt = "$a = GO FROM %ld OVER like YIELD like._src as src, like._dst as dst; "
+            "GO FROM $a.src OVER like YIELD $-.src as src, like._dst as dst";
+        auto query = folly::stringPrintf(fmt, players_["Tim Duncan"].vid());
+        auto code = client_->execute(query, resp);
+        ASSERT_EQ(cpp2::ErrorCode::E_EXECUTION_ERROR, code);
+    }
+}
+
 TEST_P(GoTest, ZeroStep) {
     // Zero step
     {