melib/jmap: construct session resource url from user settings

melib/src/backends/jmap/connection.rs

@@ -48,18 +48,27 @@ impl JmapConnection {
             .danger_accept_invalid_certs(server_conf.danger_accept_invalid_certs)
             .default_headers(headers)
             .build()?;
+        let mut jmap_session_resource_url = if server_conf.server_hostname.starts_with("https://") {
+            server_conf.server_hostname.to_string()
+        } else {
+            format!("https://{}", &server_conf.server_hostname)
+        };
+        if server_conf.server_port != 443 {
+            jmap_session_resource_url.push(':');
+            jmap_session_resource_url.extend(server_conf.server_port.to_string().chars());
+        }
+        jmap_session_resource_url.push_str("/.well-known/jmap");
+
         let req = client
-            .get(&server_conf.server_hostname)
+            .get(&jmap_session_resource_url)
             .basic_auth(
                 &server_conf.server_username,
                 Some(&server_conf.server_password),
             )
             .send()?;
         let res_text = req.text()?;
-        debug!(&res_text);
-
-        let session: JmapSession = serde_json::from_str(&res_text)?;
 
+        let session: JmapSession = serde_json::from_str(&res_text).map_err(|_| MeliError::new(format!("Could not connect to JMAP server endpoint for {}. Is your server hostname setting correct? (i.e. \"jmap.mailserver.org\") (Note: only session resource discovery via /.well-known/jmap is supported. DNS SRV records are not suppported.)", &server_conf.server_hostname)))?;
         if !session
             .capabilities
             .contains_key("urn:ietf:params:jmap:core")

melib/src/backends/jmap/operations.rs

@@ -76,7 +76,7 @@ impl BackendOp for JmapOp {
                     .client
                     .lock()
                     .unwrap()
-                    .get(&downloadRequestFormat(
+                    .get(&download_request_format(
                         &self.connection.session,
                         self.connection.mail_account_id(),
                         blob_id,

melib/src/backends/jmap/rfc8620.rs

@@ -485,7 +485,7 @@ impl<OBJ: Object> ChangesResponse<OBJ> {
     _impl!(get_mut  destroyed_mut, destroyed: Vec<String>);
 }
 
-pub fn downloadRequestFormat(
+pub fn download_request_format(
     session: &JmapSession,
     account_id: &Id,
     blob_id: &Id,
@@ -520,7 +520,7 @@ pub fn downloadRequestFormat(
     ret
 }
 
-pub fn uploadRequestFormat(session: &JmapSession, account_id: &Id) -> String {
+pub fn upload_request_format(session: &JmapSession, account_id: &Id) -> String {
     //"uploadUrl": "https://jmap.fastmail.com/upload/{accountId}/",
     let mut ret = String::with_capacity(session.upload_url.len() + account_id.len());
     let mut prev_pos = 0;