fix: Fix cookie duplication bugs

cpp/src/arrow/flight/cookie_internal.cc

@@ -64,6 +64,12 @@ size_t CaseInsensitiveHash::operator()(const std::string& key) const {
   return std::hash<std::string>{}(upper_string);
 }
 
+bool CaseInsensitiveEqual::operator()(std::string_view lhs,
+                                      std::string_view rhs) const {
+  if (lhs.size() != rhs.size()) return false;
+  return strcasecmp(std::string(lhs).c_str(), std::string(rhs).c_str()) == 0;
+}
+
 Cookie Cookie::Parse(std::string_view cookie_header_value) {
   // Parse the cookie string. If the cookie has an expiration, record it.
   // If the cookie has a max-age, calculate the current time + max_age and set that as

cpp/src/arrow/flight/cookie_internal.h

@@ -41,6 +41,12 @@ class ARROW_FLIGHT_EXPORT CaseInsensitiveComparator {
   bool operator()(const std::string& t1, const std::string& t2) const;
 };
 
+/// \brief Case insensitive equality comparator for use by unordered cookie map.
+class ARROW_FLIGHT_EXPORT CaseInsensitiveEqual {
+ public:
+  bool operator()(const std::string& lhs, const std::string& rhs) const;
+};
+
 /// \brief Case insensitive hasher for use by cookie caching map. Cookies are not
 /// case-sensitive.
 class ARROW_FLIGHT_EXPORT CaseInsensitiveHash {
@@ -117,7 +123,7 @@ class ARROW_FLIGHT_EXPORT CookieCache {
 
   // Mutex must be used to protect cookie cache.
   std::mutex mutex_;
-  std::unordered_map<std::string, Cookie, CaseInsensitiveHash, CaseInsensitiveComparator>
+  std::unordered_map<std::string, Cookie, CaseInsensitiveHash, CaseInsensitiveEqual>
       cookies;
 };
 

cpp/src/arrow/flight/sql/odbc/odbc_impl/flight_sql_connection.cc

@@ -158,9 +158,6 @@ void FlightSqlConnection::Connect(const ConnPropertyMap& properties,
     client_options_ =
         BuildFlightClientOptions(properties, missing_attr, flight_ssl_configs);
 
-    const std::shared_ptr<ClientMiddlewareFactory>& cookie_factory = GetCookieFactory();
-    client_options_.middleware.push_back(cookie_factory);
-
     std::unique_ptr<FlightClient> flight_client;
     ThrowIfNotOK(FlightClient::Connect(location, client_options_).Value(&flight_client));
     PopulateMetadataSettings(properties);