[artwork/http] Check response code and content type

Extends the http_client_ctx to hold the response code for a request.
Also adds the content type header, if it was a https request (using
libcurl instead of libevent)

src/artwork.c

@@ -206,7 +206,7 @@ static struct artwork_source artwork_item_source[] =
       .name = "Spotify web api",
       .handler = source_item_spotifywebapi_get,
       .data_kinds = (1 << DATA_KIND_SPOTIFY),
-      .cache = ON_SUCCESS,
+      .cache = ON_SUCCESS | ON_FAILURE,
     },
     {
       .name = "playlist own",
@@ -261,13 +261,14 @@ artwork_url_read(struct evbuffer *evbuf, const char *url)
   if (http_client_request(&client) < 0)
     goto out_kv;
 
+  if (client.response_code != HTTP_OK)
+    goto out_kv;
+
   content_type = keyval_get(kv, "Content-Type");
   if (content_type && (strcmp(content_type, "image/jpeg") == 0))
     ret = ART_FMT_JPEG;
   else if (content_type && (strcmp(content_type, "image/png") == 0))
     ret = ART_FMT_PNG;
-  else
-    ret = ART_FMT_JPEG;
 
  out_kv:
   keyval_clear(kv);

src/http.c

@@ -100,7 +100,6 @@ request_cb(struct evhttp_request *req, void *arg)
 {
   struct http_client_ctx *ctx;
   const char *response_code_line;
-  int response_code;
 
   ctx = (struct http_client_ctx *)arg;
 
@@ -119,21 +118,21 @@ request_cb(struct evhttp_request *req, void *arg)
       goto connection_error;
     }
 
-  response_code = evhttp_request_get_response_code(req);
+  ctx->response_code = evhttp_request_get_response_code(req);
 #ifndef HAVE_LIBEVENT2_OLD
   response_code_line = evhttp_request_get_response_code_line(req);
 #else
   response_code_line = "no error text";
 #endif
 
-  if (response_code == 0)
+  if (ctx->response_code == 0)
     {
       DPRINTF(E_WARN, L_HTTP, "Connection to %s failed: Connection refused\n", ctx->url);
       goto connection_error;
     }
-  else if (response_code != 200)
+  else if (ctx->response_code != 200)
     {
-      DPRINTF(E_WARN, L_HTTP, "Connection to %s failed: %s (error %d)\n", ctx->url, response_code_line, response_code);
+      DPRINTF(E_WARN, L_HTTP, "Connection to %s failed: %s (error %d)\n", ctx->url, response_code_line, ctx->response_code);
       goto connection_error;
     }
 
@@ -309,6 +308,23 @@ http_client_request_impl(struct http_client_ctx *ctx)
 }
 
 #ifdef HAVE_LIBCURL
+
+static void
+curl_headers_save(struct keyval *kv, CURL *curl)
+{
+  char *content_type;
+  int ret;
+
+  if (!kv || !curl)
+    return;
+
+  ret = curl_easy_getinfo(curl, CURLINFO_CONTENT_TYPE, &content_type);
+  if (ret == CURLE_OK && content_type)
+    {
+      keyval_add(kv, "Content-Type", content_type);
+    }
+}
+
 static size_t
 curl_request_cb(char *ptr, size_t size, size_t nmemb, void *userdata)
 {
@@ -341,6 +357,7 @@ https_client_request_impl(struct http_client_ctx *ctx)
   struct onekeyval *okv;
   const char *user_agent;
   char header[1024];
+  long response_code;
 
   curl = curl_easy_init();
   if (!curl)
@@ -384,6 +401,10 @@ https_client_request_impl(struct http_client_ctx *ctx)
       return -1;
     }
 
+  curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
+  ctx->response_code = (int) response_code;
+  curl_headers_save(ctx->input_headers, curl);
+
   curl_easy_cleanup(curl);
 
   return 0;

src/http.h

@@ -29,6 +29,9 @@ struct http_client_ctx
    */
   int headers_only;
 
+  /* HTTP Response code */
+  int response_code;
+
   /* Private */
   int ret;
   void *evbase;