Issue #5104 - AbstractProxyServlet include incorrect protocol version…

… in Via header when accessed over H2.

Added HttpFields.computeField() for HttpHeader too and updated usages.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>

jetty-http/src/main/java/org/eclipse/jetty/http/HttpFields.java

@@ -90,7 +90,7 @@ public HttpFields(HttpFields fields)
     }
 
     /**
-     * <p>Computes a single field for the given HTTP header name and for existing fields with the same name.</p>
+     * <p>Computes a single field for the given HttpHeader and for existing fields with the same header.</p>
      *
      * <p>The compute function receives the field name and a list of fields with the same name
      * so that their values can be used to compute the value of the field that is returned
@@ -161,17 +161,34 @@ public HttpFields(HttpFields fields)
      * httpFields.computeField("Connection", (name, fields) -&gt; null);
      * </pre>
      *
+     * @param header the HTTP header
+     * @param computeFn the compute function
+     */
+    public void computeField(HttpHeader header, BiFunction<HttpHeader, List<HttpField>, HttpField> computeFn)
+    {
+        computeField(header, computeFn, (f, h) -> f.getHeader() == h);
+    }
+
+    /**
+     * <p>Computes a single field for the given HTTP header name and for existing fields with the same name.</p>
+     *
      * @param name the HTTP header name
      * @param computeFn the compute function
+     * @see #computeField(HttpHeader, BiFunction)
      */
     public void computeField(String name, BiFunction<String, List<HttpField>, HttpField> computeFn)
+    {
+        computeField(name, computeFn, HttpField::is);
+    }
+
+    private <T> void computeField(T header, BiFunction<T, List<HttpField>, HttpField> computeFn, BiFunction<HttpField, T, Boolean> matcher)
     {
         // Look for first occurrence
         int first = -1;
         for (int i = 0; i < _size; i++)
         {
             HttpField f = _fields[i];
-            if (f.is(name))
+            if (matcher.apply(f, header))
             {
                 first = i;
                 break;
@@ -181,7 +198,7 @@ public void computeField(String name, BiFunction<String, List<HttpField>, HttpFi
         // If the header is not found, add a new one;
         if (first < 0)
         {
-            HttpField newField = computeFn.apply(name, null);
+            HttpField newField = computeFn.apply(header, null);
             if (newField != null)
                 add(newField);
             return;
@@ -192,7 +209,7 @@ public void computeField(String name, BiFunction<String, List<HttpField>, HttpFi
         for (int i = first + 1; i < _size; i++)
         {
             HttpField f = _fields[i];
-            if (f.is(name))
+            if (matcher.apply(f, header))
             {
                 if (found == null)
                 {
@@ -211,7 +228,7 @@ public void computeField(String name, BiFunction<String, List<HttpField>, HttpFi
         else
             found = Collections.unmodifiableList(found);
 
-        HttpField newField = computeFn.apply(name, found);
+        HttpField newField = computeFn.apply(header, found);
         if (newField == null)
             remove(first);
         else

jetty-http/src/test/java/org/eclipse/jetty/http/HttpFieldsTest.java

@@ -868,7 +868,7 @@ public void testStream()
     }
 
     @Test
-    public void testCompute()
+    public void testComputeField()
     {
         HttpFields header = new HttpFields();
         assertThat(header.size(), is(0));

jetty-proxy/src/main/java/org/eclipse/jetty/proxy/AbstractProxyServlet.java

@@ -554,10 +554,10 @@ protected void addViaHeader(HttpServletRequest clientRequest, Request proxyReque
         // Retain only the version if the protocol is HTTP.
         String protocolPart = parts.length == 2 && "HTTP".equalsIgnoreCase(parts[0]) ? parts[1] : protocol;
         String viaHeaderValue = protocolPart + " " + getViaHost();
-        proxyRequest.getHeaders().computeField(HttpHeader.VIA.asString(), (name, viaFields) ->
+        proxyRequest.getHeaders().computeField(HttpHeader.VIA, (header, viaFields) ->
         {
             if (viaFields == null || viaFields.isEmpty())
-                return new HttpField(name, viaHeaderValue);
+                return new HttpField(header, viaHeaderValue);
             String separator = ", ";
             String newValue = viaFields.stream()
                 .flatMap(field -> Stream.of(field.getValues()))

jetty-server/src/main/java/org/eclipse/jetty/server/handler/gzip/GzipHandler.java

@@ -662,7 +662,7 @@ public void handle(String target, Request baseRequest, HttpServletRequest reques
 
                 baseRequest.getHttpInput().addInterceptor(new GzipHttpInputInterceptor(baseRequest.getHttpChannel().getByteBufferPool(), _inflateBufferSize));
 
-                baseRequest.getHttpFields().computeField(HttpHeader.CONTENT_LENGTH.asString(), (name, fields) ->
+                baseRequest.getHttpFields().computeField(HttpHeader.CONTENT_LENGTH, (header, fields) ->
                 {
                     if (fields == null)
                         return null;