fix handling of duplicate http headers

README.md

@@ -76,6 +76,8 @@ Most of the standard Fetch API's features are supported, with the exception of:
 - Sending credentials/cookies automatically
 - Caching
 
+The response may contain multiple HTTP headers with the same name, which the `Headers` object isn't able to properly represent. If this matters to you, use `response.raw_headers`, which is an array of key value pairs, instead of `response.headers`.
+
 Note that there is a hard limit of 50 active TCP connections due to emscripten limitations. 
 
 ### Creating WebSocket Connections:

client/javascript/main.js

@@ -132,8 +132,11 @@ function create_response(response_data, response_info) {
     writable: false,
     value: new Headers()
   });
-  for (let header_name in response_info.headers) {
-    let header_value = response_info.headers[header_name];
+  Object.defineProperty(response_obj, "raw_headers", {
+    writable: false,
+    value: response_info.headers
+  });
+  for (let [header_name, header_value] of response_info.headers) {
     response_obj.headers.append(header_name, header_value);
   }
   

client/libcurl/main.c

@@ -167,12 +167,16 @@ void finish_request(CURLMsg *curl_msg) {
   cJSON* url_item = cJSON_CreateString(response_url);
   cJSON_AddItemToObject(response_json, "url", url_item);
 
-  cJSON* headers_item = cJSON_CreateObject();
+  cJSON* headers_item = cJSON_CreateArray();
   struct curl_header *prev_header = NULL;
   struct curl_header *header = NULL;
   while ((header = curl_easy_nextheader(http_handle, CURLH_HEADER, -1, prev_header))) {
-    cJSON* header_entry = cJSON_CreateString(header->value);
-    cJSON_AddItemToObject(headers_item, header->name, header_entry);
+    cJSON* header_key_entry = cJSON_CreateString(header->name);
+    cJSON* header_value_entry = cJSON_CreateString(header->value);
+    cJSON* header_pair_item = cJSON_CreateArray();
+    cJSON_AddItemToArray(header_pair_item, header_key_entry);
+    cJSON_AddItemToArray(header_pair_item, header_value_entry);
+    cJSON_AddItemToArray(headers_item, header_pair_item);
     prev_header = header;
   }
   cJSON_AddItemToObject(response_json, "headers", headers_item);

client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "libcurl.js",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "An experimental port of libcurl to WebAssembly for use in the browser.",
   "main": "libcurl.mjs",
   "scripts": {