Fix argMin/argMax combinator state

src/AggregateFunctions/Combinators/AggregateFunctionCombinatorsArgMinArgMax.cpp

@@ -68,9 +68,9 @@ public:
     String getName() const override
     {
         if constexpr (isMin)
-            return "ArgMin";
+            return nested_function->getName() + "ArgMin";
         else
-            return "ArgMax";
+            return nested_function->getName() + "ArgMax";
     }
 
     bool isState() const override { return nested_function->isState(); }

tests/queries/0_stateless/03127_argMin_combinator_state.reference

@@ -0,0 +1,12 @@
+AggregateFunction(sumArgMin, UInt64, UInt64)
+54
+0	45
+1	46
+2	47
+3	48
+4	49
+5	50
+6	51
+7	52
+8	53
+9	54

tests/queries/0_stateless/03127_argMin_combinator_state.sql

@@ -0,0 +1,22 @@
+SELECT toTypeName(sumArgMinState(number, number)) FROM numbers(1);
+SELECT sumArgMinState(number, number) AS a FROM numbers(3) FORMAT Null;
+
+DROP TABLE IF EXISTS argmax_comb;
+CREATE TABLE argmax_comb(
+        id UInt64,
+        state AggregateFunction(avgArgMax, Float64, UInt64)
+    )
+    ENGINE=MergeTree() ORDER BY tuple();
+INSERT INTO argmax_comb
+    SELECT
+        CAST(number % 10, 'UInt64') AS id,
+        avgArgMaxState(CAST(number, 'Float64'), id)
+    FROM numbers(100)
+    GROUP BY id;
+SELECT avgArgMaxMerge(state) FROM argmax_comb;
+SELECT
+    id,
+    avgArgMaxMerge(state)
+FROM argmax_comb
+GROUP BY id
+ORDER BY id ASC;