Merge pull request #2927 from dolthub/nicktobey/binary

Converting a nil value should return nil, not panic.

Author: nicktobey

enginetest/queries/queries.go

@@ -5206,6 +5206,17 @@ SELECT * FROM cte WHERE  d = 2;`,
 		Query:    "SELECT CAST(-3 AS DOUBLE) FROM dual",
 		Expected: []sql.Row{{-3.0}},
 	},
+	{
+		Query: "SELECT BINARY c, BINARY vc, BINARY t, BINARY b, BINARY vb, BINARY bl FROM niltexttable",
+		Expected: []sql.Row{
+			{nil, nil, nil, nil, nil, nil},
+			{[]byte("2"), nil, []byte("2"), nil, []byte("2"), nil},
+			{nil, []byte("3"), []byte("3"), nil, nil, []byte("3")},
+			{[]byte("4"), []byte("4"), nil, []byte("4\x00"), nil, nil},
+			{nil, nil, nil, []byte("5\x00"), []byte("5"), []byte("5")},
+			{[]byte("6"), []byte("6"), []byte("6"), []byte("6\x00"), []byte("6"), []byte("6")},
+		},
+	},
 	{
 		Query:    `SELECT CONVERT("-3.9876", FLOAT) FROM dual`,
 		Expected: []sql.Row{{float32(-3.9876)}},

enginetest/scriptgen/setup/scripts/niltable

@@ -21,3 +21,26 @@ insert into niltable values
 exec
 create index niltable_i2 on niltable (i2)
 ----
+
+exec
+CREATE TABLE `niltexttable` (
+  `i` bigint NOT NULL,
+  `c` char(2),
+  `vc` varchar(2),
+  `t` text,
+  `b` binary(2),
+  `vb` varbinary(2),
+  `bl` blob,
+  PRIMARY KEY (`i`)
+)
+----
+
+exec
+insert into niltexttable values
+    (1, null, null, null, null, null, null),
+    (2, '2',  null, '2',  null, '2',  null),
+    (3, null, '3',  '3',  null, null, '3'),
+    (4, '4',  '4',  null, '4',  null, null),
+    (5, null, null, null, '5',  '5',  '5'),
+    (6, '6',  '6',  '6',  '6',  '6',  '6')
+----

enginetest/scriptgen/setup/setup_data.sg.go

@@ -284,6 +284,9 @@ func (c *Convert) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 // converted type where applicable (e.g. Char conversion supports only |typeLength|, Decimal conversion supports
 // |typeLength| and |typeScale|).
 func convertValue(ctx *sql.Context, val interface{}, castTo string, originType sql.Type, typeLength, typeScale int) (interface{}, error) {
+	if val == nil {
+		return nil, nil
+	}
 	switch strings.ToLower(castTo) {
 	case ConvertToBinary:
 		b, _, err := types.LongBlob.Convert(ctx, val)