expression: ignore TypeNULL in HandleBinaryLiteral (pingcap#49527) (pingcap#49532)

close pingcap#49526

Author: ti-chi-bot

DEPS.bzl

@@ -5463,14 +5463,16 @@ def go_deps():
         name = "com_sourcegraph_sourcegraph_appdash",
         build_file_proto_mode = "disable_global",
         importpath = "sourcegraph.com/sourcegraph/appdash",
-        sum = "h1:ucqkfpjg9WzSUubAO62csmucvxl4/JeW3F4I4909XkM=",
+        replace = "github.com/sourcegraph/appdash",
+        sum = "h1:IJ3DuWHPTJrsqtIqjfdmPTELdTFGefvrOa2eTeRBleQ=",
         version = "v0.0.0-20190731080439-ebfcffb1b5c0",
     )
     go_repository(
         name = "com_sourcegraph_sourcegraph_appdash_data",
         build_file_proto_mode = "disable_global",
         importpath = "sourcegraph.com/sourcegraph/appdash-data",
-        sum = "h1:e1sMhtVq9AfcEy8AXNb8eSg6gbzfdpYhoNqnPJa+GzI=",
+        replace = "github.com/sourcegraph/appdash-data",
+        sum = "h1:8ZnTA26bBOoPkAbbitKPgNlpw0Bwt7ZlpYgZWHWJR/w=",
         version = "v0.0.0-20151005221446-73f23eafcf67",
     )
     go_repository(

expression/builtin_convert_charset.go

@@ -322,7 +322,8 @@ func HandleBinaryLiteral(ctx sessionctx.Context, expr Expression, ec *ExprCollat
 				return expr
 			}
 			return BuildToBinaryFunction(ctx, expr)
-		} else if argChs == charset.CharsetBin && dstChs != charset.CharsetBin {
+		} else if argChs == charset.CharsetBin && dstChs != charset.CharsetBin &&
+			expr.GetType().GetType() != mysql.TypeNull {
 			ft := expr.GetType().Clone()
 			ft.SetCharset(ec.Charset)
 			ft.SetCollate(ec.Collation)

expression/integration_test/integration_test.go

@@ -7971,3 +7971,14 @@ func TestIssue41986(t *testing.T) {
 	// shouldn't report they can't find column error and return the right result.
 	tk.MustQuery("SELECT GROUP_CONCAT(effective_date order by stlmnt_hour DESC) FROM ( SELECT (COALESCE(pct.clearing_time, 0)/3600000) AS stlmnt_hour ,COALESCE(pct.effective_date, '1970-01-01 08:00:00') AS effective_date FROM poi_clearing_time_topic pct ORDER BY pct.effective_date DESC ) a;").Check(testkit.Rows("2023-08-25 00:00:00"))
 }
+
+func TestIssue49526(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+
+	rows := tk.MustQuery("explain select null as a union all select 'a' as a;").Rows()
+	for _, r := range rows {
+		require.NotContains(t, r[4], "from_binary")
+	}
+	tk.MustQuery("select null as a union all select 'a' as a;").Sort().Check(testkit.Rows("<nil>", "a"))
+}

go.mod

@@ -296,4 +296,9 @@ replace (
 	github.com/go-ldap/ldap/v3 => github.com/YangKeao/ldap/v3 v3.4.5-0.20230421065457-369a3bab1117
 	github.com/pingcap/tidb/parser => ./parser
 	go.opencensus.io => go.opencensus.io v0.23.1-0.20220331163232-052120675fac
+
+	// TODO: `sourcegraph.com/sourcegraph/appdash` has been archived, and the original host has been removed.
+	// Please remove these dependencies.
+	sourcegraph.com/sourcegraph/appdash => github.com/sourcegraph/appdash v0.0.0-20190731080439-ebfcffb1b5c0
+	sourcegraph.com/sourcegraph/appdash-data => github.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67
 )

go.sum

@@ -912,6 +912,10 @@ github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
 github.com/soheilhy/cmux v0.1.5 h1:jjzc5WVemNEDTLwv9tlmemhC73tI08BNOIGwBOo10Js=
 github.com/soheilhy/cmux v0.1.5/go.mod h1:T7TcVDs9LWfQgPlPsdngu6I6QIoyIFZDDC6sNE1GqG0=
+github.com/sourcegraph/appdash v0.0.0-20190731080439-ebfcffb1b5c0 h1:IJ3DuWHPTJrsqtIqjfdmPTELdTFGefvrOa2eTeRBleQ=
+github.com/sourcegraph/appdash v0.0.0-20190731080439-ebfcffb1b5c0/go.mod h1:V952P4GGl1v/MMynLwxVdWEbSZJx+n0oOO3ljnez+WU=
+github.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67 h1:8ZnTA26bBOoPkAbbitKPgNlpw0Bwt7ZlpYgZWHWJR/w=
+github.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67/go.mod h1:tNZjgbYncKL5HxvDULAr/mWDmFz4B7H8yrXEDlnoIiw=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
 github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
@@ -1616,9 +1620,5 @@ sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=
 sigs.k8s.io/yaml v1.2.0/go.mod h1:yfXDCHCao9+ENCvLSE62v9VSji2MKu5jeNfTrofGhJc=
 sigs.k8s.io/yaml v1.3.0 h1:a2VclLzOGrwOHDiV8EfBGhvjHvP46CtW5j6POvhYGGo=
 sigs.k8s.io/yaml v1.3.0/go.mod h1:GeOyir5tyXNByN85N/dRIT9es5UQNerPYEKK56eTBm8=
-sourcegraph.com/sourcegraph/appdash v0.0.0-20190731080439-ebfcffb1b5c0 h1:ucqkfpjg9WzSUubAO62csmucvxl4/JeW3F4I4909XkM=
-sourcegraph.com/sourcegraph/appdash v0.0.0-20190731080439-ebfcffb1b5c0/go.mod h1:hI742Nqp5OhwiqlzhgfbWU4mW4yO10fP+LoT9WOswdU=
-sourcegraph.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67 h1:e1sMhtVq9AfcEy8AXNb8eSg6gbzfdpYhoNqnPJa+GzI=
-sourcegraph.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67/go.mod h1:L5q+DGLGOQFpo1snNEkLOJT2d1YTW66rWNzatr3He1k=
 stathat.com/c/consistent v1.0.0 h1:ezyc51EGcRPJUxfHGSgJjWzJdj3NiMU9pNfLNGiXV0c=
 stathat.com/c/consistent v1.0.0/go.mod h1:QkzMWzcbB+yQBL2AttO6sgsQS/JSTapcDISJalmCDS0=