tools400 opened a new pull request, #26573: URL: https://github.com/apache/camel/pull/26573
ExchangeHelper.replaceMessage() fetches old via exchange.getMessage(), which returns the current IN message when there is no OUT message yet. When TransformProcessor replaces a specialized (non-DefaultMessage) IN message with outOnly=true, old ends up being the same instance as exchange.getIn(). The method then sets the new message as OUT, leaving IN untouched, but unconditionally detaches old's exchange reference via messageSupport.setExchange(null), so the IN message stays attached to the exchange while itself reporting a null exchange. Normally the next pipeline step calls ExchangeHelper.prepareOutToIn, promoting OUT to IN and reattaching it, which hides the dangling reference. When transform is the last step of a route, this never happens, and BacklogTracerRouteAdvice#after crashes with a NullPointerException while dumping exchange.getIn() for tracing (only reached when the backlog tracer is enabled, or in standby mode with message history enabled, as camel-debug sets up in Quarkus dev mode). Only detach old from the exchange in replaceMessage() when it is no longer referenced as IN or OUT afterwards. Add regression tests in ExchangeHelperTest covering replaceMessage() with and without an existing OUT message, and a new TransformLastStepBacklogTracerNpeTest exercising the full route scenario with a DefaultMessage subclass (as platform-http and http create) and transform as the last step. # Description The pull request fixes an NPE that occurs when `transform` is the last step of a route and the incoming message is a subclass of `DefaultMessage` (as created by `platform-http`, `http`, and other components), while the backlog tracer is active. # Target - [x] I checked that the commit is targeting the correct branch (Camel 4 uses the `main` branch) # Tracking - [ ] If this is a large change, bug fix, or code improvement, I checked there is a [JIRA issue](https://issues.apache.org/jira/browse/CAMEL) filed for the change (usually before you start working on it). <!-- # *Note*: trivial changes like, typos, minor documentation fixes and other small items do not require a JIRA issue. In this case your pull request should address just this issue, without pulling in other changes. --> # Apache Camel coding standards and style - [x] I checked that each commit in the pull request has a meaningful subject line and body. <!-- If you're unsure, you can format the pull request title like `[CAMEL-XXX] Fixes bug in camel-file component`, where you replace `CAMEL-XXX` with the appropriate JIRA issue. --> - [ ] I have run `mvn clean install -DskipTests` locally from root folder and I have committed all auto-generated changes. <!-- You can run the aforementioned command in your module so that the build auto-formats your code. This will also be verified as part of the checks and your PR may be rejected if if there are uncommited changes after running `mvn clean install -DskipTests`. You can learn more about the contribution guidelines at https://github.com/apache/camel/blob/main/CONTRIBUTING.md --> # AI-assisted contributions - [x] If this PR includes AI-generated code, commits have proper co-authorship attribution (e.g., `Co-authored-by` trailers) and the PR description identifies the AI tool used. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
