Trailing / in backend ProxyTo URL causes routing error

[willmostly]

A trailing slash in the proxyTo URL, e.g.

{"name": "my-proxy-target", "routingGroup":"adhoc", "ProxyTo": "https://my-proxy-target.io/", "ExternalUrl": "https://my-proxy-target.io/"}

will produce a URL like https://my-proxy-target.io//v1/statement. Double slashes in the path are illegal, and will produce an obscure error message such as

org.eclipse.jetty.http.BadMessageException: 400: Ambiguous URI empty segment at 
org.eclipse.jetty.server.internal.HttpConnection$HttpStreamOverHTTP1.headerComplete(HttpConnection.java:1194) at 
org.eclipse.jetty.server.internal.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:959) at 
org.eclipse.jetty.http.HttpParser.parseFields(HttpParser.java:1350) at 
org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:1646) at 
org.eclipse.jetty.server.internal.HttpConnection.parseRequestBuffer(HttpConnection.java:575) at 
org.eclipse.jetty.server.internal.HttpConnection.onFillable(HttpConnection.java:382) at 
org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:322) at 
org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:99) at 
org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53) at 
org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.runTask(AdaptiveExecutionStrategy.java:478) at 
org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.consumeTask(AdaptiveExecutionStrategy.java:441) at 
org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.tryProduce(AdaptiveExecutionStrategy.java:293) at 
org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.run(AdaptiveExecutionStrategy.java:201) at 
org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:311) at 
org.eclipse.jetty.util.thread.MonitoredQueuedThreadPool$1.run(MonitoredQueuedThreadPool.java:73) at 
org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:979) at 
org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1209) at 
org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1164) at 
java.base/java.lang.Thread.run(Thread.java:1575)

[neshatadyen]

Thank you for sharing it! We're experimenting Trino Gateway and it would be difficult to find the issue for us if you haven't shared this