build: bump cpp-httplib to 0.47.0

conan.lock

@@ -13,7 +13,7 @@
         "miniz/3.0.2#bfbce07c6654293cce27ee24129d2df7%1743673472.805",
         "gtest/1.14.0#f8f0757a574a8dd747d16af62d6eb1b7%1743410807.169",
         "cryptopp/8.9.0#7a51e0038756b21bc3a6b82d681d5906%1758206597.119",
-        "cpp-httplib/0.16.3#7aa89fbb81ffd19539a49fc132502966%1748426320.106",
+        "cpp-httplib/0.47.0#add6673ff352c26898ed2650453e706e%1784539639.401",
         "bzip2/1.0.8#c470882369c2d95c5c77e970c0c7e321%1762886692.465",
         "argon2/20190702-odr#965901884bc82ec8a7c0a1305d42c127%1784987057.981858"
     ],

conanfile.py

@@ -54,7 +54,7 @@ def requirements(self):
         self.requires("uchardet/0.0.8")
         self.requires("utfcpp/4.0.9")
         if self.options.get_safe("with_http_server", False):
-            self.requires("cpp-httplib/0.16.3")
+            self.requires("cpp-httplib/0.47.0")
         self.requires("argon2/20190702-odr")
         if self.options.get_safe("with_python", False):
             self.requires("pybind11/2.13.6")

src/odr/http_server.cpp

@@ -215,6 +215,9 @@ class HttpServer::Impl : public std::enable_shared_from_this<Impl> {
                          ? static_cast<int>(port)
                          : -1);
     if (bound < 0) {
+      // a failed bind decommissions the server and only stop() clears that, so
+      // without this no later bind - a fallback to any port - could succeed
+      m_server->stop();
       throw ServerBindFailed(host, port);
     }
 

test/src/http_server_test.cpp

@@ -53,6 +53,20 @@ TEST(HttpServer, bind_reports_a_port_in_use) {
   taken.stop();
 }
 
+TEST(HttpServer, bind_can_be_retried_after_it_failed) {
+  const HttpServer taken;
+  const std::uint32_t port = taken.bind("127.0.0.1", 0);
+
+  // falling back to any port is the reason a failed bind may not be terminal:
+  // cpp-httplib decommissions the server on one, and only stop() undoes that
+  const HttpServer other;
+  EXPECT_THROW(other.bind("127.0.0.1", port), ServerBindFailed);
+  EXPECT_NE(other.bind("127.0.0.1", 0), 0);
+
+  other.stop();
+  taken.stop();
+}
+
 TEST(HttpServer, listen_without_bind_is_refused) {
   const HttpServer server;