Accept connection records without topic field (#6)

The field is not present in ROS Noetic rosbags.

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.6.3 - 2024-05-27
+### Changed
+- Accept connection records without `topic` field ([#6])
+
+[#6]: https://github.com/newpavlov/rosbag-rs/pull/6
+
 ## 0.6.2 - 2024-05-22
 ### Changed
 - Accept empty `latching` field in connection headers ([#5])

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rosbag"
-version = "0.6.2"
+version = "0.6.3"
 description = "Utilities for reading ROS bag files."
 authors = ["Artyom Pavlov <newpavlov@gmail.com>"]
 license = "MIT OR Apache-2.0"

src/record_types/connection.rs

@@ -85,7 +85,7 @@ impl<'a> RecordGen<'a> for Connection<'a> {
             }
         }
 
-        let topic = topic.ok_or(Error::InvalidHeader)?;
+        let topic = topic.unwrap_or(storage_topic);
         let tp = tp.ok_or(Error::InvalidHeader)?;
         let md5sum = md5sum.ok_or(Error::InvalidHeader)?;
         let message_definition = message_definition.ok_or(Error::InvalidHeader)?;