From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 10 Jul 2021 12:36:36 +0000 (+0100)
Subject: script: lower: Bail early if no targets
X-Git-Tag: otter-0.7.2~159
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=552f62adf0957a35113f55594144d2422a0ab2d0;p=otter.git

script: lower: Bail early if no targets

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/templates/script.ts b/templates/script.ts
index 150353b0..e43819c1 100644
--- a/templates/script.ts
+++ b/templates/script.ts
@@ -646,10 +646,13 @@ function lower_pieces(targets_todo: LowerTodoList):
   let bottommost_unbottom : Entry | null = null;
 
   let n_targets_todo_unbottom = 0;
+  let any_targets = false;
   for (const piece of Object.keys(targets_todo)) {
+    any_targets = true;
     let p = targets_todo[piece];
     if (!p.bottom) n_targets_todo_unbottom++;
   }
+  if (!any_targets) return 'Nothing to lower!';
 
   let walk = pieces_marker;
   for (;;) { // starting at the bottom of the stack order