nghttpx: Call request phase hook for pushed resource as well

doc/nghttpx.h2r

@@ -289,7 +289,10 @@ and :rb:attr:`Nghttpx::Env#resp` respectively.
         method is noop.  *uri* can be absolute URI, absolute path or
         relative path to the current request.  For absolute or
         relative path, scheme and authority are inherited from the
-        current request.  Currently, method is always GET.
+        current request.  Currently, method is always GET.  nghttpx
+        will issue request to backend servers to fulfill this request.
+        The request and response phase hooks will be called for pushed
+        resource as well.
 
 .. rb:class:: Response
 

src/shrpx_http2_upstream.cc

@@ -587,6 +587,20 @@ int on_frame_send_callback(nghttp2_session *session, const nghttp2_frame *frame,
     // downstream is in pending queue.
     auto ptr = downstream.get();
     upstream->add_pending_downstream(std::move(downstream));
+
+#ifdef HAVE_MRUBY
+    auto worker = handler->get_worker();
+    auto mruby_ctx = worker->get_mruby_context();
+
+    if (mruby_ctx->run_on_request_proc(ptr) != 0) {
+      if (upstream->error_reply(ptr, 500) != 0) {
+        upstream->rst_stream(ptr, NGHTTP2_INTERNAL_ERROR);
+        return 0;
+      }
+      return 0;
+    }
+#endif // HAVE_MRUBY
+
     upstream->start_downstream(ptr);
 
     return 0;