From 769a6dfb0882bbfdd10447781a6a1f0f4c7c9319 Mon Sep 17 00:00:00 2001
From: "philip.han" <philip.han@kakaocorp.com>
Date: Fri, 17 Jul 2020 18:21:25 +0900
Subject: [PATCH] bayseAB returns an empty block if input_rows_count is 0 and
 isDeterministic returns false

---
 src/Functions/abtesting.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/Functions/abtesting.cpp b/src/Functions/abtesting.cpp
index 061a941a78f..52131908087 100644
--- a/src/Functions/abtesting.cpp
+++ b/src/Functions/abtesting.cpp
@@ -141,6 +141,9 @@ public:
         return name;
     }
 
+    bool isDeterministic() const override { return false; }
+    bool isDeterministicInScopeOfQuery() const override { return false; }
+
     size_t getNumberOfArguments() const override { return 5; }
 
     DataTypePtr getReturnTypeImpl(const DataTypes &) const override
@@ -148,8 +151,14 @@ public:
         return std::make_shared<DataTypeString>();
     }
 
-    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t) override
+    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t input_rows_count) override
     {
+        if (input_rows_count == 0)
+        {
+            block.getByPosition(result).column = std::move(ColumnString::create());
+            return;
+        }
+
         std::vector<double> xs, ys;
         std::vector<std::string> variant_names;
         String dist;