vcpkg/ports/nghttp2-asio/0001-Fix-exception-in-server.patch

From b4745aa3d87916c7d3da33c00da400b22a0539b5 Mon Sep 17 00:00:00 2001
From: m8mble <m8mble@vivaldi.net>
Date: Fri, 20 Jan 2023 16:36:30 +0100
Subject: [PATCH 1/1] Fix exception in server

It can happen that a connection handler calls writefun when the
connection is already destroyed. This causes bad_weak_ptr exceptions
thrown from the server.

Fix this issue by skipping the respective do_write invocations.

Signed-off-by: m8mble <m8mble@vivaldi.net>
---
 lib/asio_server_connection.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/asio_server_connection.h b/lib/asio_server_connection.h
index a948965..94ed59f 100644
--- a/lib/asio_server_connection.h
+++ b/lib/asio_server_connection.h
@@ -88,9 +88,20 @@ public:
   void start() {
     boost::system::error_code ec;
 
+    auto make_writefun = [original_self = this->shared_from_this()] {
+        return [weak = std::weak_ptr<connection>{original_self}]() {
+            auto self = weak.lock();
+            // If connection already got destroyed, the socket is already closed in particular.
+            // Therefore we can simply ignore further calls to write.
+            if (self) {
+                self->do_write();
+            }
+        };
+    };
+
     handler_ = std::make_shared<http2_handler>(
         GET_IO_SERVICE(socket_), socket_.lowest_layer().remote_endpoint(ec),
-        [this]() { do_write(); }, mux_);
+        make_writefun(), mux_);
     if (handler_->start() != 0) {
       stop();
       return;
-- 
2.39.1