add ffi for update_device_chats()

deltachat-ffi/deltachat.h

@@ -1139,6 +1139,24 @@ void            dc_set_draft                 (dc_context_t* context, uint32_t ch
 uint32_t        dc_add_device_msg            (dc_context_t* context, const char* label, dc_msg_t* msg);
 
 
+/**
+ * Init device-messages and saved-messages chat.
+ * This function adds the device-chat and saved-messages chat
+ * and adds one or more welcome or update-messages.
+ * The ui can add messages on its own using dc_add_device_msg() -
+ * for ordering, either before or after or even without calling this function.
+ *
+ * Chat and message creation is done only once.
+ * So if the user has manually deleted things, they won't be re-created
+ * (however, not seen device messages are added and may re-create the device-chat).
+ *
+ * @memberof dc_context_t
+ * @param context The context as created by dc_context_new().
+ * @return None.
+ */
+void            dc_update_device_chats       (dc_context_t* context);
+
+
 /**
  * Check if a device-message with a given label was ever added.
  * Device-messages can be added dc_add_device_msg().

deltachat-ffi/src/lib.rs

@@ -851,6 +851,21 @@ pub unsafe extern "C" fn dc_add_device_msg(
         .unwrap_or(0)
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn dc_update_device_chats(context: *mut dc_context_t) {
+    if context.is_null() {
+        eprintln!("ignoring careless call to dc_update_device_chats()");
+        return;
+    }
+    let ffi_context = &mut *context;
+    ffi_context
+        .with_inner(|ctx| {
+            ctx.update_device_chats()
+                .unwrap_or_log_default(ctx, "Failed to add device message")
+        })
+        .unwrap_or(())
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_was_device_msg_ever_added(
     context: *mut dc_context_t,