Re-check field type under write lock.

CHANGELOG.md

@@ -19,6 +19,8 @@
 - [#8044](https://github.com/influxdata/influxdb/issues/8044): Treat non-reserved measurement names with underscores as normal measurements.
 - [#8078](https://github.com/influxdata/influxdb/issues/8078): Map types correctly when selecting a field with multiple measurements where one of the measurements is empty.
 - [#8080](https://github.com/influxdata/influxdb/issues/8080): Point.UnmarshalBinary() bounds check
+- [#8085](https://github.com/influxdata/influxdb/issues/8085): panic: interface conversion: tsm1.Value is tsm1.IntegerValue, not tsm1.FloatValue.
+
 
 ## v1.2.0 [2017-01-24]
 

tsdb/shard.go

@@ -1134,7 +1134,12 @@ func (m *MeasurementFields) CreateFieldIfNotExists(name string, typ influxql.Dat
 
 	m.mu.Lock()
 	defer m.mu.Unlock()
+
+	// Re-check field and type under write lock.
 	if f := m.fields[name]; f != nil {
+		if f.Type != typ {
+			return ErrFieldTypeConflict
+		}
 		return nil
 	}