refactor

driver_test.go

@@ -150,9 +150,8 @@ func runTests(t *testing.T, dsn string, tests ...func(dbt *DBTest)) {
 		t.Fatalf("connecting %q: %s", dsn, err)
 	}
 	defer db.Close()
-
-	cleanup := func() {
-		db.Exec("DROP TABLE IF EXISTS test")
+	if err = db.Ping(); err != nil {
+		t.Fatalf("connecting %q: %s", dsn, err)
 	}
 
 	dsn2 := dsn + "&interpolateParams=true"
@@ -173,23 +172,31 @@ func runTests(t *testing.T, dsn string, tests ...func(dbt *DBTest)) {
 	}
 	defer db3.Close()
 
+	cleanupSql := "DROP TABLE IF EXISTS test"
+
 	for _, test := range tests {
 		test := test
 		t.Run("default", func(t *testing.T) {
 			dbt := &DBTest{t, db}
-			t.Cleanup(cleanup)
+			t.Cleanup(func() {
+				db.Exec(cleanupSql)
+			})
 			test(dbt)
 		})
 		if db2 != nil {
 			t.Run("interpolateParams", func(t *testing.T) {
 				dbt2 := &DBTest{t, db2}
-				t.Cleanup(cleanup)
+				t.Cleanup(func() {
+					db2.Exec(cleanupSql)
+				})
 				test(dbt2)
 			})
 		}
 		t.Run("compress", func(t *testing.T) {
 			dbt3 := &DBTest{t, db3}
-			t.Cleanup(cleanup)
+			t.Cleanup(func() {
+				db3.Exec(cleanupSql)
+			})
 			test(dbt3)
 		})
 	}

packets.go

@@ -28,7 +28,7 @@ import (
 // Read packet to buffer 'data'
 func (mc *mysqlConn) readPacket() ([]byte, error) {
 	var prevData []byte
-	invalid := false
+	invalidSequence := false
 
 	readNext := mc.buf.readNext
 	if mc.compress {
@@ -67,8 +67,7 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
 					mc.close()
 					return nil, ErrPktSyncMul
 				}
-				// TODO(methane): report error when the packet is not an error packet.
-				invalid = true
+				invalidSequence = true
 			}
 			mc.sequence++
 		}
@@ -99,19 +98,18 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
 		// return data if this was the last packet
 		if pktLen < maxPacketSize {
 			// zero allocations for non-split packets
-			if prevData == nil {
-				if invalid {
-					mc.close()
-					// return sync error only for regular packet.
-					// error packets may have wrong sequence number.
-					if data[0] != iERR {
-						return nil, ErrPktSync
-					}
+			if prevData != nil {
+				data = append(prevData, data...)
+			}
+			if invalidSequence {
+				mc.close()
+				// return sync error only for regular packet.
+				// error packets may have wrong sequence number.
+				if data[0] != iERR {
+					return nil, ErrPktSync
 				}
-				return data, nil
 			}
-
-			return append(prevData, data...), nil
+			return data, nil
 		}
 
 		prevData = append(prevData, data...)