expression: handle tp.flen overflow in to_base64 function (#20947) (#…

…21813) Signed-off-by: ti-srebot <[email protected]>
pingcap · Jan 25, 2021 · d6756cf · d6756cf
1 parent e4526c7
commit d6756cf
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/expression/builtin_string.go b/expression/builtin_string.go
@@ -3549,7 +3549,7 @@ func (b *builtinToBase64Sig) evalString(row chunk.Row) (d string, isNull bool, e
 		return "", true, nil
 	}
 	if b.tp.Flen == -1 || b.tp.Flen > mysql.MaxBlobWidth {
-		return "", true, nil
+		b.tp.Flen = mysql.MaxBlobWidth
 	}
 
 	//encode

diff --git a/expression/builtin_string_vec.go b/expression/builtin_string_vec.go
@@ -2420,8 +2420,7 @@ func (b *builtinToBase64Sig) vecEvalString(input *chunk.Chunk, result *chunk.Col
 			result.AppendNull()
 			continue
 		} else if b.tp.Flen == -1 || b.tp.Flen > mysql.MaxBlobWidth {
-			result.AppendNull()
-			continue
+			b.tp.Flen = mysql.MaxBlobWidth
 		}
 
 		newStr := base64.StdEncoding.EncodeToString([]byte(str))

diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -7294,6 +7294,19 @@ func (s *testIntegrationSuite) TestIssue17476(c *C) {
 	tk.MustQuery(`SELECT * FROM (table_int_float_varchar AS tmp3) WHERE (col_varchar_6 AND NULL) IS NULL AND col_int_6=0;`).Check(testkit.Rows("13 0 -0.1 <nil>"))
 }
 
+func (s *testIntegrationSuite) TestIssue14349(c *C) {
+	defer s.cleanEnv(c)
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test;")
+	tk.MustExec("drop table if exists papers;")
+	tk.MustExec("create table papers(title text, content longtext)")
+	tk.MustExec("insert into papers values('title', 'content')")
+	tk.MustQuery(`select to_base64(title), to_base64(content) from papers;`).Check(testkit.Rows("dGl0bGU= Y29udGVudA=="))
+	tk.MustExec("set tidb_enable_vectorized_expression = 0;")
+	tk.MustQuery(`select to_base64(title), to_base64(content) from papers;`).Check(testkit.Rows("dGl0bGU= Y29udGVudA=="))
+	tk.MustExec("set tidb_enable_vectorized_expression = 1;")
+}
+
 func (s *testIntegrationSuite) TestIssue20180(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")