Http filter recieves null response in a case of an error

[dstepanov]

Expected Behavior

No exception

Actual Behaviour

Null value is set for the response:

java.lang.NullPointerException: Cannot invoke "io.micronaut.http.MutableHttpResponse.getHeaders()" because "mutableHttpResponse" is null
        at benchmark.filter.ServerHeaderFilter.addDateHeader(ServerHeaderFilter.java:30)
        at benchmark.filter.$ServerHeaderFilter$Definition$Exec.dispatch(Unknown Source)
        at io.micronaut.context.AbstractExecutableMethodsDefinition$DispatchedExecutableMethod.invokeUnsafe(AbstractExecutableMethodsDefinition.java:461)
        at io.micronaut.http.filter.MethodFilter.filter0(MethodFilter.java:342)
        at io.micronaut.http.filter.MethodFilter.filter(MethodFilter.java:331)
        at io.micronaut.http.filter.MethodFilter.processResponseFilter(MethodFilter.java:305)
        at io.micronaut.http.filter.FilterRunner.filterResponse(FilterRunner.java:220)

Steps To Reproduce

No response

Environment Information

No response

Example Application

No response

Version

4.4

[dstepanov]

Only occurs for async controller methods

[dstepanov]

I can reproduce it on the benchmark project:

• Revert the latest performance changes
• Set maximum-pool-size: 512
• /gradlew micronaut-vertx-pg-client:run
• http://localhost:8080/prepare-data-for-test
• wrk -H 'Host: localhost' -H 'Accept: application/json,text/html;q=0.9,application/xhtml+xml;q=0.9,application/xml;q=0.8,*/*;q=0.7' -H 'Connection: keep-alive' --latency -d 150 -c 512 --timeout 8 -t 128 "http://localhost:8080/db"

• java.lang.NullPointerException: Cannot invoke "io.micronaut.http.MutableHttpResponse.header(java.lang.CharSequence, java.lang.CharSequence)" because "mutableHttpResponse" is null
      at benchmark.filter.ServerHeaderFilter.addDateHeader(ServerHeaderFilter.java:28)
      at benchmark.filter.$ServerHeaderFilter$Definition$Exec.dispatch(Unknown Source)
      at io.micronaut.context.AbstractExecutableMethodsDefinition$DispatchedExecutableMethod.invokeUnsafe(AbstractExecutableMethodsDefinition.java:461)
      at io.micronaut.http.filter.MethodFilter.filter0(MethodFilter.java:342)
      at io.micronaut.http.filter.MethodFilter.filter(MethodFilter.java:331)
      at io.micronaut.http.filter.MethodFilter.processResponseFilter(MethodFilter.java:305)
      at io.micronaut.http.filter.FilterRunner.filterResponse(FilterRunner.java:220)
      at io.micronaut.http.filter.FilterRunner.lambda$run$1(FilterRunner.java:163)
      at io.micronaut.core.execution.CompletableFutureExecutionFlowImpl.lambda$flatMap$0(CompletableFutureExecutionFlowImpl.java:51)
      at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150)
      at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
      at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2194)
      at io.vertx.core.Future.lambda$toCompletionStage$3(Future.java:583)
      at io.vertx.core.impl.future.FutureImpl$4.onFailure(FutureImpl.java:188)
      at io.vertx.core.impl.future.FutureBase.emitFailure(FutureBase.java:81)
      at io.vertx.core.impl.future.FutureImpl.tryFail(FutureImpl.java:278)
      at io.vertx.core.impl.future.Mapping.onFailure(Mapping.java:45)