fixup: must not use teco_view_save_to_file() when creating backup/recovery filesHEADmaster-fmsbw-cimaster

* It emits undo tokens which would bring internal datastructures - especially the undo stack -
  out of sync.
* We now document that teco_view_save_to_channel() will always be without undo token emission.

2 files changed, 23 insertions, 1 deletions

diff --git a/src/ring.c b/src/ring.c
index e42ff14..afd6b25 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -334,11 +334,26 @@ teco_ring_backup(void)
 			continue;
 
 		g_autofree gchar *filename_backup = teco_buffer_get_backup(buffer);
+
+		g_autoptr(GIOChannel) channel = g_io_channel_new_file(filename_backup, "w", NULL);
+		if (!channel)
+			continue;
+
 		/*
+		 * teco_view_save_to_channel() expects a buffered and blocking channel.
+		 */
+		g_io_channel_set_encoding(channel, NULL, NULL);
+		g_io_channel_set_buffered(channel, TRUE);
+
+		/*
+		 * This does not use teco_view_save_to_file() since we must not
+		 * emit undo tokens.
+		 *
 		 * FIXME: Errors are silently ignored.
 		 * Should we log warnings instead?
 		 */
-		teco_view_save(buffer->view, filename_backup, NULL);
+		if (!teco_view_save_to_channel(buffer->view, channel, NULL))
+			continue;
 
 		buffer->state = TECO_BUFFER_DIRTY_BACKEDUP;
 	}
diff --git a/src/view.c b/src/view.c
index eeb4d3d..d5b5d14 100644
--- a/src/view.c
+++ b/src/view.c
@@ -508,6 +508,13 @@ teco_undo_remove_file_push(const gchar *filename)
 		strcpy(ctx, filename);
 }
 
+/**
+ * Save the view's document to the given IO channel.
+ *
+ * @note This must not emit undo tokens as it is also used by teco_ring_backup().
+ *
+ * @memberof teco_view_t
+ */
 gboolean
 teco_view_save_to_channel(teco_view_t *ctx, GIOChannel *channel, GError **error)
 {