fix: improve handling of asterisk in HTTP/2 ':path' pseudo-header

Author: He-Pin

http-core/src/main/scala/org/apache/pekko/http/impl/engine/http2/hpack/HeaderDecompression.scala

@@ -76,12 +76,9 @@ private[http2] final class HeaderDecompression(masterHeaderParser: HttpHeaderPar
               }
 
               name match {
-                case "content-type" => handle(ContentType.parse(name, value, parserSettings))
-                case ":authority"   => handle(Authority.parse(name, value, parserSettings))
-                case ":path"        =>
-                  if (value.isEmpty)
-                    throw new Http2ProtocolException("Malformed request: ':path' must not be empty")
-                  handle(PathAndQuery.parse(name, value, parserSettings))
+                case "content-type"   => handle(ContentType.parse(name, value, parserSettings))
+                case ":authority"     => handle(Authority.parse(name, value, parserSettings))
+                case ":path"          => handle(PathAndQuery.parse(name, value, parserSettings))
                 case ":method"        => handle(Method.parse(name, value, parserSettings))
                 case ":scheme"        => handle(Scheme.parse(name, value, parserSettings))
                 case "content-length" => handle(ContentLength.parse(name, value, parserSettings))

http-core/src/main/scala/org/apache/pekko/http/impl/model/parser/UriParser.scala

@@ -351,7 +351,8 @@ private[http] final class UriParser(
   // https://tools.ietf.org/html/rfc7540#section-8.1.2.3
   def `http2-path-pseudo-header` = rule(
     `absolute-path` ~ optional('?' ~ rawQueryString) // origin-form
-  ) // TODO: asterisk-form
+    | '*' ~ run(setPath(Path.Empty)) ~ run { _rawQueryString = None } // asterisk-form (for OPTIONS requests)
+  )
 
   /**
    * @return path and percent-encoded query string. When in in 'relaxed' mode, characters not permitted by https://tools.ietf.org/html/rfc3986#section-3.4

http2-tests/src/test/scala/org/apache/pekko/http/impl/engine/http2/RequestParsingSpec.scala

@@ -449,13 +449,15 @@ class RequestParsingSpec extends PekkoSpecWithMaterializer with Inside with Insp
       // ... A request in asterisk form includes the
       // value '*' for the ":path" pseudo-header field.
 
-      "handle a ':path' with an asterisk" in pendingUntilFixed {
+      "handle a ':path' with an asterisk" in {
         val request: HttpRequest = parseExpectOk(
           keyValuePairs = Vector(
             ":method" -> "OPTIONS",
             ":scheme" -> "http",
-            ":path" -> "*"))
-        request.uri.toString should ===("*") // FIXME: Compare in a better way
+            ":path" -> "*"
+          ))
+        request.uri.path.toString should ===("")
+        request.uri.rawQueryString should ===(None)
       }
 
       // [The ":path"] pseudo-header field MUST NOT be empty for "http" or "https"