Not creating auto MR in GitLab when we use fast forward merge strategy

[aswiniabi]

We tested ucascade with gitlab project which is having fast forward merge strategy and its not creating the auto MR. We got this below error , Exception while creating auto merge request. Project: '58879255', User: '19282984', SourceBranch: 'dev/1.2.x', TargetBranch: 'develop', MergeRequestNumber: '8', MergeSha: 'null'\njava.lang.IllegalArgumentException: ref cannot be empty or null\n\tat org.gitlab4j.api.AbstractApi.addFormParam(AbstractApi.java:645)\n\tat org.gitlab4j.api.RepositoryFileApi.getFile(RepositoryFileApi.java:169)\n\tat org.gitlab4j.api.RepositoryFileApi.getFile(RepositoryFileApi.java:123)\n\tat service.GitLabService.getBranchModelConfigurationFile(GitLabService.java:486)\n\tat service.GitLabService.createAutoMr(GitLabService.java:202)\n\tat service.GitLabService.handleMrMergeEvent(GitLabService.java:135)\n\tat service.GitLabService.mergeRequest(GitLabService.java:94)\n\tat service.GitLabService_ClientProxy.mergeRequest(Unknown Source)\n\tat service.GitLabService_VertxInvoker_mergeRequest_a4d1c2c568052411df78f735c61ae86d3766853c.invokeBean(Unknown Source)\n\tat io.quarkus.vertx.runtime.EventConsumerInvoker.invoke(EventConsumerInvoker.java:41)\n\tat io.quarkus.vertx.runtime.VertxRecorder$3$1$1.handle(VertxRecorder.java:116)\n\tat io.quarkus.vertx.runtime.VertxRecorder$3$1

There was an error rendering this math block. KaTeX parse error: Undefined control sequence: \n at position 33: …order.java:112)\̲n̲\tat io.vertx.c…
null

There was an error rendering this math block. KaTeX parse error: Undefined control sequence: \n at position 24: …tBase.java:137)\̲n̲\tat io.vertx.c…
executeBlocking$1(ContextBase.java:135)\n\tat io.quarkus.vertx.core.runtime.VertxCoreRecorder

There was an error rendering this math block. KaTeX parse error: Undefined control sequence: \n at position 39: …order.java:576)\̲n̲\tat org.jboss.…
Task.run(EnhancedQueueExecutor.java:2449)\n\tat org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1478)\n\tat org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29)\n\tat org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29)\n\tat io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)\n\tat java.base/java.lang.Thread.run(Thread.java:833)\n","severity":"WARNING","timestamp":{"seconds":1727366774,"nanos":252056398},"logging.googleapis.com/sourceLocation":{"file":"GitLabService.java","line":"137","function":"service.GitLabService.handleMrMergeEvent"}}.

We gone through the code for cascading request and found object_attributes.merge_commit_sha is being sent as null but the solution appears to require it to have the value found in object_attributes.merge_params.sha. Please assist.

[fbpe]

We managed to reproduce the problem when the merge is done without a merge commit (fast-forward).

With #35 we are adding support to the FF strategy. Please try it out and let us know.