From b9c42effb48d7ef15a5f8f269bbe67145d2c8cd1 Mon Sep 17 00:00:00 2001
From: taiyang-li <654010905@qq.com>
Date: Sat, 5 Feb 2022 19:30:40 +0800
Subject: [PATCH] change as requested

---
 src/Functions/FunctionsStringArray.h          | 39 +++++++++----------
 .../0_stateless/02185_split_by_char.sql       |  1 -
 2 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/src/Functions/FunctionsStringArray.h b/src/Functions/FunctionsStringArray.h
index dcd9198ef33f..b1de017120c6 100644
--- a/src/Functions/FunctionsStringArray.h
+++ b/src/Functions/FunctionsStringArray.h
@@ -244,8 +244,8 @@ class SplitByCharImpl
     Pos end;
 
     char sep;
-    Int64 max_split = -1;
-    Int64 curr_split = 0;
+    std::optional<UInt64> max_split;
+    UInt64 curr_split = 0;
 
 public:
     static constexpr auto name = "splitByChar";
@@ -295,15 +295,14 @@ class SplitByCharImpl
 
         if (arguments.size() > 2)
         {
-            std::optional<Int64> max_split_opt = std::nullopt;
-            if (!((max_split_opt = getMaxSplit<UInt8>(arguments[2]))
-                || (max_split_opt = getMaxSplit<Int8>(arguments[2]))
-                || (max_split_opt = getMaxSplit<UInt16>(arguments[2]))
-                || (max_split_opt = getMaxSplit<Int16>(arguments[2]))
-                || (max_split_opt = getMaxSplit<UInt32>(arguments[2]))
-                || (max_split_opt = getMaxSplit<Int32>(arguments[2]))
-                || (max_split_opt = getMaxSplit<UInt64>(arguments[2]))
-                || (max_split_opt = getMaxSplit<Int64>(arguments[2]))))
+            if (!((max_split = getMaxSplit<UInt8>(arguments[2]))
+                || (max_split = getMaxSplit<Int8>(arguments[2]))
+                || (max_split = getMaxSplit<UInt16>(arguments[2]))
+                || (max_split = getMaxSplit<Int16>(arguments[2]))
+                || (max_split = getMaxSplit<UInt32>(arguments[2]))
+                || (max_split = getMaxSplit<Int32>(arguments[2]))
+                || (max_split = getMaxSplit<UInt64>(arguments[2]))
+                || (max_split = getMaxSplit<Int64>(arguments[2]))))
             {
                 throw Exception(
                     ErrorCodes::ILLEGAL_COLUMN,
@@ -311,23 +310,21 @@ class SplitByCharImpl
                     arguments[2].column->getName(),
                     getName());
             }
-            max_split = *max_split_opt;
         }
     }
 
     template <typename DataType>
-    std::optional<Int64> getMaxSplit(const ColumnWithTypeAndName & argument)
+    std::optional<UInt64> getMaxSplit(const ColumnWithTypeAndName & argument)
     {
         const auto * col = checkAndGetColumnConst<ColumnVector<DataType>>(argument.column.get());
         if (!col)
             return std::nullopt;
 
-        Int64 result= static_cast<Int64>(col->template getValue<DataType>());
-        if (result < 0 && result != -1)
-            throw Exception("Illegal column " + argument.column->getName()
-                + " of third argument of function " + getName() + ". Must be non-negative number or -1",
-                ErrorCodes::ILLEGAL_COLUMN);
-        return result;
+        auto value = col->template getValue<DataType>();
+        if (value < 0)
+            throw Exception(
+                ErrorCodes::ILLEGAL_COLUMN, "Illegal column {} of third argument of function {}", argument.column->getName(), getName());
+        return value;
     }
 
     /// Returns the position of the argument, that is the column of strings
@@ -348,14 +345,14 @@ class SplitByCharImpl
             return false;
 
         token_begin = pos;
-        if (unlikely(max_split >= 0 && curr_split >= max_split))
+        if (unlikely(max_split && curr_split >= *max_split))
         {
             token_end = end;
             pos = nullptr;
             return true;
         }
-        pos = reinterpret_cast<Pos>(memchr(pos, sep, end - pos));
 
+        pos = reinterpret_cast<Pos>(memchr(pos, sep, end - pos));
         if (pos)
         {
             token_end = pos;
diff --git a/tests/queries/0_stateless/02185_split_by_char.sql b/tests/queries/0_stateless/02185_split_by_char.sql
index 6b843c05144a..6c4906548137 100644
--- a/tests/queries/0_stateless/02185_split_by_char.sql
+++ b/tests/queries/0_stateless/02185_split_by_char.sql
@@ -1,5 +1,4 @@
 select splitByChar(',', '1,2,3');
-select splitByChar(',', '1,2,3', -1);
 select splitByChar(',', '1,2,3', 0);
 select splitByChar(',', '1,2,3', 1);
 select splitByChar(',', '1,2,3', 2);