From 5a884da13c6994a591551ec190d9bda6169e796a Mon Sep 17 00:00:00 2001
From: Evgeniy Gatov <egatov@yandex-team.ru>
Date: Wed, 14 Jul 2021 23:05:57 +0300
Subject: [PATCH] METR-41529

---
 src/IO/ReadHelpers.cpp                         |  1 +
 tests/queries/0_stateless/01946_test.reference |  0
 tests/queries/0_stateless/01946_tskv.reference |  1 +
 tests/queries/0_stateless/01946_tskv.sh        | 15 +++++++++++++++
 4 files changed, 17 insertions(+)
 create mode 100644 tests/queries/0_stateless/01946_test.reference
 create mode 100644 tests/queries/0_stateless/01946_tskv.reference
 create mode 100755 tests/queries/0_stateless/01946_tskv.sh

diff --git a/src/IO/ReadHelpers.cpp b/src/IO/ReadHelpers.cpp
index 2a5594a6866..e695809871c 100644
--- a/src/IO/ReadHelpers.cpp
+++ b/src/IO/ReadHelpers.cpp
@@ -327,6 +327,7 @@ static void parseComplexEscapeSequence(Vector & s, ReadBuffer & buf)
             && decoded_char != '"'
             && decoded_char != '`'  /// MySQL style identifiers
             && decoded_char != '/'  /// JavaScript in HTML
+            && decoded_char != '='  /// Yandex's TSKV
             && !isControlASCII(decoded_char))
         {
             s.push_back('\\');
diff --git a/tests/queries/0_stateless/01946_test.reference b/tests/queries/0_stateless/01946_test.reference
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/queries/0_stateless/01946_tskv.reference b/tests/queries/0_stateless/01946_tskv.reference
new file mode 100644
index 00000000000..5a3b19fa88f
--- /dev/null
+++ b/tests/queries/0_stateless/01946_tskv.reference
@@ -0,0 +1 @@
+can contain = symbol
diff --git a/tests/queries/0_stateless/01946_tskv.sh b/tests/queries/0_stateless/01946_tskv.sh
new file mode 100755
index 00000000000..ecc18d205d2
--- /dev/null
+++ b/tests/queries/0_stateless/01946_tskv.sh
@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+$CLICKHOUSE_CLIENT --query="DROP TABLE IF EXISTS tskv";
+$CLICKHOUSE_CLIENT --query="CREATE TABLE tskv (text String) ENGINE = Memory";
+
+# shellcheck disable=SC2028
+echo -n 'tskv	text=can contain \= symbol
+' | $CLICKHOUSE_CLIENT --query="INSERT INTO tskv FORMAT TSKV";
+
+$CLICKHOUSE_CLIENT --query="SELECT * FROM tskv";
+$CLICKHOUSE_CLIENT --query="DROP TABLE tskv";