Add a test for #2719

tests/queries/0_stateless/01812_basic_auth_http_server.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+# In very old (e.g. 1.1.54385) versions of ClickHouse there was a bug in Poco HTTP library:
+# Basic HTTP authentication headers was not parsed if the size of URL is exactly 4077 + something bytes.
+# So, the user may get authentication error if valid credentials are passed.
+# This is a minor issue because it does not have security implications (at worse the user will be not allowed to access).
+
+CUR_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CUR_DIR"/../shell_config.sh
+
+# In this test we do the opposite: passing the invalid credentials while server is accepting default user without a password.
+# And if the bug exists, they will be ignored (treat as empty credentials) and query succeed.
+
+for i in {3950..4100}; do ${CLICKHOUSE_CURL} --user default:12345 "${CLICKHOUSE_URL}&query=SELECT+1"$(perl -e "print '+'x$i") | grep -v -F 'password' && echo 'Fail'; done
+
+# You can check that the bug exists in old version by running the old server in Docker:
+# docker run --network host -it --rm yandex/clickhouse-server:1.1.54385