Passing an empty Host header to an HTTP 1.1 request results in a StringOutOfBoundException

[jamezp]

Expected Behavior

The request should use a default host or at least not attempt to check the first character of an empty host. This issue seemed to be introduced here a3e6d37#diff-c53be0aa1c780a295ce5c742f574d0633894044b87e7ff68c01da79af95e5f65R68. It seems the simple solution would be to do:

if (header != null && !header.isEmpty())

Actual Behavior

You end up getting the following error:

15:52:54,501 WARNING [reactor.netty.http.server.HttpServerOperations] (reactor-http-nio-2) [7d6754c8, L:/127.0.0.1:8081 - R:/127.0.0.1:50526] Decoding failed: REQUEST(decodeResult: failure(java.lang.StringIndexOutOfBoundsException: String index out of range: 0), version: HTTP/1.1)
GET /uriinfo HTTP/1.1
Host: <filtered>
Connection: <filtered>

Steps to Reproduce

Simply pass a header like:

Host:

Possible Solution

Check if the Host header is blank/empty before attempting to substring the header value.

Your Environment

• Reactor version(s) used: 2022.0.4
• Other relevant libraries versions (eg. netty, ...): Netty 4.1.89.Final
• JVM version (java -version): OpenJDK 64-Bit Server VM (Red_Hat-11.0.18.0.10-1.fc37) (build 11.0.18+10, mixed mode, sharing)
• OS and version (eg. uname -a): Linux localhost 6.1.14-200.fc37.x86_64 MonoHttpClientChannel subscribes to Mono with a null subscriber #1 SMP PREEMPT_DYNAMIC Sun Feb 26 00:13:26 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

[violetagg]

@jamezp Thanks for reporting the issue. PTAL #2724