Allow user to store the current url in the session before going to th…

…e IDP

src/agent/mod.rs

@@ -460,6 +460,8 @@ where
         let client = self.client.as_ref().ok_or(OAuth2Error::NotInitialized)?;
         let config = self.config.as_ref().ok_or(OAuth2Error::NotInitialized)?;
 
+        let post_login_url = Self::current_url().map_err(OAuth2Error::StartLogin)?;
+
         // take the parameter value first, then the agent configured value, then fall back to the default
         let redirect_url = match options.redirect_url.or_else(|| {
             config
@@ -471,6 +473,11 @@ where
             None => Self::current_url().map_err(OAuth2Error::StartLogin)?,
         };
 
+        if redirect_url != post_login_url {
+            SessionStorage::set(STORAGE_KEY_POST_LOGIN_URL, post_login_url)
+                .map_err(|err| OAuth2Error::StartLogin(err.to_string()))?;
+        }
+
         let login_context = client.make_login_context(config, redirect_url.clone())?;
 
         SessionStorage::set(STORAGE_KEY_CSRF_TOKEN, login_context.csrf_token)

src/agent/state.rs

@@ -1,6 +1,7 @@
 pub const STORAGE_KEY_CSRF_TOKEN: &str = "ctron/oauth2/csrfToken";
 pub const STORAGE_KEY_LOGIN_STATE: &str = "ctron/oauth2/loginState";
 pub const STORAGE_KEY_REDIRECT_URL: &str = "ctron/oauth2/redirectUrl";
+pub const STORAGE_KEY_POST_LOGIN_URL: &str = "ctron/oauth2/postLoginUrl";
 
 #[derive(Debug)]
 pub struct State {