[gnome-calendar/mcatanzaro/webcal] source-discoverer: add support for webcal:// URIs

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 4990adc578f447c468239fb9022313c7bde4562c
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Thu Apr 2 17:39:22 2020 -0500

    source-discoverer: add support for webcal:// URIs
    
    We can implement webcal:// by simply rewriting the URI to https://.
    Amazing!
    
    Fixes #564

 src/utils/gcal-source-discoverer.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)
---
diff --git a/src/utils/gcal-source-discoverer.c b/src/utils/gcal-source-discoverer.c
index 6c61cdab..1bcca5bd 100644
--- a/src/utils/gcal-source-discoverer.c
+++ b/src/utils/gcal-source-discoverer.c
@@ -216,16 +216,29 @@ discover_file_in_thread (DiscovererData  *data,
   g_autoptr (SoupMessage) message = NULL;
   g_autoptr (SoupSession) session = NULL;
   g_autoptr (GPtrArray) source = NULL;
+  g_autoptr (SoupURI) uri = NULL;
+  g_autofree char *uri_str = NULL;
   const gchar *content_type;
 
   GCAL_ENTRY;
 
-  GCAL_TRACE_MSG ("Creating request for %s", data->uri);
+  uri = soup_uri_new (data->uri);
+
+  /* Support webcal:// links by converting them to https://.
+   *
+   * We don't allow hidden use of http://, since we want to protect the
+   * user from accidentally leaking calendars in the clear.
+   */
+  if (strcmp (uri->scheme, "webcal") == 0)
+    soup_uri_set_scheme (uri, SOUP_URI_SCHEME_HTTPS);
+
+  uri_str = soup_uri_to_string (uri, FALSE);
+  GCAL_TRACE_MSG ("Creating request for %s", uri_str);
 
   session = soup_session_new_with_options (SOUP_SESSION_TIMEOUT, 10, NULL);
   g_signal_connect (session, "authenticate", G_CALLBACK (on_soup_session_authenticate_cb), data);
 
-  message = soup_message_new ("GET", data->uri);
+  message = soup_message_new_from_uri ("GET", uri);
   input_stream = soup_session_send (session, message, cancellable, error);
 
   if (!input_stream)