todo: avoid checkout in sequencer.c

builtin/rebase.c

@@ -1423,13 +1423,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		    state_dir_base, cmd_live_rebase, buf.buf);
 	}
 
-	if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
-	    (options.action != ACTION_NONE) ||
-	    (options.exec.nr > 0) ||
-	    (options.autosquash == -1 && options.config_autosquash == 1) ||
-	    options.autosquash == 1) {
+	if (options.action != ACTION_NONE)
 		allow_preemptive_ff = 0;
-	}
+
 	if (options.committer_date_is_author_date || options.ignore_date)
 		options.flags |= REBASE_FORCE;
 
@@ -1597,6 +1593,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	switch (options.type) {
 	case REBASE_MERGE:
 		options.state_dir = merge_dir();
+		allow_preemptive_ff = 0;
 		break;
 	case REBASE_APPLY:
 		options.state_dir = apply_dir();