sam: make sure all commands can be undone

Take a snapshot before and after processing the transcript.

1 files changed, 2 insertions, 0 deletions

diff --git a/sam.c b/sam.c
index d1cc637..fc41e57 100644
--- a/sam.c
+++ b/sam.c
@@ -1137,6 +1137,7 @@ enum SamError sam_cmd(Vis *vis, const char *s) {
 			err = t->error;
 			continue;
 		}
+		vis_file_snapshot(vis, file);
 		ptrdiff_t delta = 0;
 		for (Change *c = t->changes; c; c = c->next) {
 			c->range.start += delta;
@@ -1176,6 +1177,7 @@ enum SamError sam_cmd(Vis *vis, const char *s) {
 			}
 		}
 		sam_transcript_free(&file->transcript);
+		vis_file_snapshot(vis, file);
 	}
 
 	if (vis->win) {