StaticHandlerImpl is trying to write to response that is closed

[juddgaddie]

Version

This occurs in vertx-web version 3.5.2 and 3.6.2 (with corresponding vertx core)

Context

I encountered an exception in my CI environment, while it does not result in unexpected behaviour it does fill my logs with errors. This error occurs in the VertX provided StaticHandlerImpl when Firefox 57.0.4 is attempting to download /thirdparty/fonts/glyphicons-halflings-regular.woff

java.lang.IllegalStateException: Response is closed
	at io.vertx.core.http.impl.HttpServerResponseImpl.checkValid(HttpServerResponseImpl.java:564)
	at io.vertx.core.http.impl.HttpServerResponseImpl.putHeader(HttpServerResponseImpl.java:158)
	at io.vertx.core.http.impl.HttpServerResponseImpl.putHeader(HttpServerResponseImpl.java:55)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendFile$11(StaticHandlerImpl.java:423)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.wrapInTCCLSwitch(StaticHandlerImpl.java:261)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.sendFile(StaticHandlerImpl.java:412)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$null$0(StaticHandlerImpl.java:227)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.getFileProps(StaticHandlerImpl.java:312)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendStatic$1(StaticHandlerImpl.java:204)
	at io.vertx.core.impl.ContextImpl.lambda$null$0(ContextImpl.java:284)
	at io.vertx.core.impl.ContextImpl.executeTask(ContextImpl.java:320)
	at io.vertx.core.impl.EventLoopContext.lambda$executeAsync$0(EventLoopContext.java:38)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:474)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)

[juddgaddie]

Additionally this exception from the StaticHandler is thrown which may be related. Just guessing here but if the Channel (TCP socket) is closed but close() is not called on HTTPServerResponseImpl then when the response is attempted to be written the channel is closed and hence the exception below.

java.nio.channels.ClosedChannelException
	at io.netty.handler.stream.ChunkedWriteHandler.discard(ChunkedWriteHandler.java:172)
	at io.netty.handler.stream.ChunkedWriteHandler.doFlush(ChunkedWriteHandler.java:198)
	at io.netty.handler.stream.ChunkedWriteHandler.flush(ChunkedWriteHandler.java:135)
	at io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776)
	at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768)
	at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749)
	at io.netty.channel.ChannelDuplexHandler.flush(ChannelDuplexHandler.java:117)
	at io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:802)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814)
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794)
	at io.vertx.core.net.impl.ConnectionBase.write(ConnectionBase.java:102)
	at io.vertx.core.net.impl.ConnectionBase.writeToChannel(ConnectionBase.java:112)
	at io.vertx.core.http.impl.Http1xServerConnection.writeToChannel(Http1xServerConnection.java:298)
	at io.vertx.core.net.impl.ConnectionBase.sendFile(ConnectionBase.java:312)
	at io.vertx.core.http.impl.Http1xServerConnection.sendFile(Http1xServerConnection.java:522)
	at io.vertx.core.http.impl.HttpServerResponseImpl.doSendFile(HttpServerResponseImpl.java:459)
	at io.vertx.core.http.impl.HttpServerResponseImpl.sendFile(HttpServerResponseImpl.java:378)
	at io.vertx.core.http.HttpServerResponse.sendFile(HttpServerResponse.java:329)
	at io.vertx.core.http.HttpServerResponse.sendFile(HttpServerResponse.java:315)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendFile$11(StaticHandlerImpl.java:477)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.wrapInTCCLSwitch(StaticHandlerImpl.java:261)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.sendFile(StaticHandlerImpl.java:412)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$null$0(StaticHandlerImpl.java:227)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.getFileProps(StaticHandlerImpl.java:312)
	at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendStatic$1(StaticHandlerImpl.java:204)
	at io.vertx.core.impl.ContextImpl.lambda$null$0(ContextImpl.java:284)
	at io.vertx.core.impl.ContextImpl.executeTask(ContextImpl.java:320)
	at io.vertx.core.impl.EventLoopContext.lambda$executeAsync$0(EventLoopContext.java:38)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:474)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)

[pmlopes]

A check should be added before the call:

at io.vertx.ext.web.handler.impl.StaticHandlerImpl.lambda$sendFile$11(StaticHandlerImpl.java:477)

[juddgaddie]

Much appreciated.