From f53654150ab2117fc1d3f5d1563c1265f2f64f02 Mon Sep 17 00:00:00 2001
From: Zhigao Tong <tongzhigao@pingcap.com>
Date: Wed, 20 Jul 2022 21:41:55 +0800
Subject: [PATCH] Fix

---
 dbms/src/Storages/Transaction/Collator.cpp | 15 +++++-------
 tests/fullstack-test/expr/like.test        | 27 +++++++++++++++++++++-
 2 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/dbms/src/Storages/Transaction/Collator.cpp b/dbms/src/Storages/Transaction/Collator.cpp
index 1b0221a6829..d11d693a8a4 100644
--- a/dbms/src/Storages/Transaction/Collator.cpp
+++ b/dbms/src/Storages/Transaction/Collator.cpp
@@ -92,15 +92,12 @@ class Pattern : public ITiDBCollator::IPattern
                 tp = MatchType::Match;
                 if (offset < pattern.length())
                 {
-                    auto old_offset = offset;
-                    c = Collator::decodeChar(pattern.data(), old_offset);
-                    if (c == escape || c == '_' || c == '%')
-                        offset = old_offset;
-                    else
-                    {
-                        assert(escape >= 0);
-                        c = static_cast<decltype(c)>(escape); // NOLINT(bugprone-signed-char-misuse)
-                    }
+                    // use next char to match
+                    c = Collator::decodeChar(pattern.data(), offset);
+                }
+                else
+                {
+                    // use `escape` to match
                 }
             }
             else if (c == '_')
diff --git a/tests/fullstack-test/expr/like.test b/tests/fullstack-test/expr/like.test
index af76095d157..5f13c7a8159 100644
--- a/tests/fullstack-test/expr/like.test
+++ b/tests/fullstack-test/expr/like.test
@@ -38,4 +38,29 @@ mysql> set @@tidb_isolation_read_engines='tiflash'; select * from test.t where '
 | a    | b    |
 +------+------+
 | aaaa | %a%  |
-+------+------+
\ No newline at end of file
++------+------+
+
+mysql> insert into test.t values ('1234', '');
+
+mysql> set @@tidb_isolation_read_engines='tiflash'; select a from test.t where a like '1234' escape '4';
++------+
+| a    |
++------+
+| 1234 |
++------+
+
+mysql> set @@tidb_isolation_read_engines='tiflash'; select a from test.t where a like '1234' escape '2';
+
+mysql> set @@tidb_isolation_read_engines='tiflash'; select a from test.t where a like '15234' escape '5';
++------+
+| a    |
++------+
+| 1234 |
++------+
+
+mysql> set @@tidb_isolation_read_engines='tiflash'; select a from test.t where a like '_223_' escape '2';
++------+
+| a    |
++------+
+| 1234 |
++------+