Get back 01281_group_by_limit_memory_tracking (without flackiness)

tests/queries/0_stateless/01281_group_by_limit_memory_tracking.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+
+# Regression for MemoryTracker that had been incorrectly accounted
+# (it was reseted before deallocation)
+#
+# For this will be used:
+# - two-level group by
+# - max_memory_usage_for_user
+# - one users' query in background (to avoid reseting max_memory_usage_for_user)
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+. $CURDIR/../shell_config.sh
+
+set -o pipefail
+
+function execute_null()
+{
+    ${CLICKHOUSE_CLIENT} --format Null -n "$@"
+}
+
+function execute_group_by()
+{
+    local opts=(
+        --max_memory_usage_for_user=$((150<<20))
+        --max_threads=2
+    )
+    execute_null "${opts[@]}" <<<'SELECT uniq(number) FROM numbers_mt(toUInt64(1e6)) GROUP BY number % 5e5'
+}
+
+execute_null <<<'SELECT sleep(3)' &
+execute_group_by
+# if memory accounting will be incorrect, the second query will be failed with MEMORY_LIMIT_EXCEEDED
+execute_group_by
+wait