Fix bug preventing GET params from being read on parametrized URLs. (#326)

This also introduces tests to verify the bug doesn't return.

The bug was due to the populate_args method checking whether the
cache was empty before executing. By doing so, it was ignoring that
in case of parametrized URLs, the webserver class was loading the
params as arguments.

Co-authored-by: Merlino <merlinos@147dda0f5bcf.ant.amazon.com>

Author: etr

src/http_request.cpp

@@ -105,13 +105,15 @@ const http::header_view_map http_request::get_cookies() const {
 }
 
 void http_request::populate_args() const {
-    if (!cache->unescaped_args.empty()) {
+    if (cache->args_populated) {
         return;
     }
     arguments_accumulator aa;
     aa.unescaper = unescaper;
     aa.arguments = &cache->unescaped_args;
     MHD_get_connection_values(underlying_connection, MHD_GET_ARGUMENT_KIND, &build_request_args, reinterpret_cast<void*>(&aa));
+
+    cache->args_populated = true;
 }
 
 http_arg_value http_request::get_arg(std::string_view key) const {

src/httpserver/http_request.hpp

@@ -410,6 +410,8 @@ class http_request {
         std::string requestor_ip;
         std::string digested_user;
         std::map<std::string, std::vector<std::string>, http::arg_comparator> unescaped_args;
+
+        bool args_populated = false;
      };
      std::unique_ptr<http_request_data_cache> cache = std::make_unique<http_request_data_cache>();
      // Populate the data cache unescaped_args

test/integ/basic.cpp

@@ -948,6 +948,24 @@ LT_BEGIN_AUTO_TEST(basic_suite, regex_matching_arg)
     curl_easy_cleanup(curl);
 LT_END_AUTO_TEST(regex_matching_arg)
 
+LT_BEGIN_AUTO_TEST(basic_suite, regex_matching_arg_with_url_pars)
+    args_resource resource;
+    LT_ASSERT_EQ(true, ws->register_resource("this/captures/{arg}/passed/in/input", &resource));
+    curl_global_init(CURL_GLOBAL_ALL);
+
+    string s;
+    CURL *curl = curl_easy_init();
+    CURLcode res;
+    curl_easy_setopt(curl, CURLOPT_URL, "localhost:" PORT_STRING "/this/captures/whatever/passed/in/input?arg2=second_argument");
+    curl_easy_setopt(curl, CURLOPT_HTTPGET, 1L);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &s);
+    res = curl_easy_perform(curl);
+    LT_ASSERT_EQ(res, 0);
+    LT_CHECK_EQ(s, "whateversecond_argument");
+    curl_easy_cleanup(curl);
+LT_END_AUTO_TEST(regex_matching_arg_with_url_pars)
+
 LT_BEGIN_AUTO_TEST(basic_suite, regex_matching_arg_custom)
     args_resource resource;
     LT_ASSERT_EQ(true, ws->register_resource("this/captures/numeric/{arg|([0-9]+)}/passed/in/input", &resource));