commit a00719e9ec7fca4511eb77a8aee31bd098f52c68
from: Stefan Sperling <stsp@stsp.name>
date: Fri Jun 17 11:01:26 2022 UTC

fix a segfault in tog diff

The f1 tempfile must always be created. Even if the initial diff has no
objects on the left side, the view can be switched to a different diff
which does have objects on both sides. When that happened, tog crashed.
(To reproduce: open tog in got.git, hit G, hit Enter, hit <)

commit - dd6e31d7e33e64ea324b0afe932b3a509d7d963e
commit + a00719e9ec7fca4511eb77a8aee31bd098f52c68
blob - 3a68d826936ce61d03cad367b5fbd52ed10c4298
blob + 8782d2289745425a1fdaecbd1edbcab6c230e7e6
--- tog/tog.c
+++ tog/tog.c
@@ -3830,11 +3830,6 @@ open_diff_view(struct tog_view *view, struct got_objec
 		s->id1 = got_object_id_dup(id1);
 		if (s->id1 == NULL)
 			return got_error_from_errno("got_object_id_dup");
-		s->f1 = got_opentemp();
-		if (s->f1 == NULL) {
-			err = got_error_from_errno("got_opentemp");
-			goto done;
-		}
 	} else
 		s->id1 = NULL;
 
@@ -3844,6 +3839,12 @@ open_diff_view(struct tog_view *view, struct got_objec
 		goto done;
 	}
 
+	s->f1 = got_opentemp();
+	if (s->f1 == NULL) {
+		err = got_error_from_errno("got_opentemp");
+		goto done;
+	}
+
 	s->f2 = got_opentemp();
 	if (s->f2 == NULL) {
 		err = got_error_from_errno("got_opentemp");