#1743: choose default names around protected overflow paths

crates/engine/src/output_guard.rs

@@ -621,18 +621,20 @@ impl Session {
             let Ok(outputs) = self.outputs_of(item, None) else { break };
             let mut in_the_way = false;
             for (module, path) in &outputs {
-                match self.check_output(&protected, module, path) {
-                    Ok(Some(_)) => in_the_way = true,
-                    Err(_) => {
-                        item.output.output = template;
-                        return;
-                    }
-                    Ok(None) => {}
-                }
                 let Ok(paths) = self.write_paths(module, path) else {
                     item.output.output = template;
                     return;
                 };
+                for destination in &paths {
+                    match self.check_output(&protected, module, destination) {
+                        Ok(Some(_)) => in_the_way = true,
+                        Err(_) => {
+                            item.output.output = template;
+                            return;
+                        }
+                        Ok(None) => {}
+                    }
+                }
                 in_the_way |= paths.iter().any(|path| queue.clash(&self.write_of(module, path, false)).is_some());
             }
             if !in_the_way {

crates/engine/src/tests/render_overwrite.rs

@@ -695,6 +695,19 @@ fn possible_storage_overflow_destinations_cannot_replace_footage() {
     assert_eq!(f.read("overflow/Main.mp4"), SOURCE);
 }
 
+#[test]
+fn default_names_avoid_protected_storage_overflow_destinations() {
+    let mut f = Fixture::new("overflow-protected-default");
+    f.comp("Main");
+    with_overflow(&mut f);
+    f.footage("overflow/Main.mp4");
+    f.add(json!({"storageOverflow": true}));
+    assert_eq!(f.output(0), f.path("Main_1.mp4"));
+    f.render(json!({})).unwrap();
+    assert_eq!(f.exported().len(), 1);
+    assert_eq!(f.read("overflow/Main.mp4"), SOURCE);
+}
+
 /// After Effects numbers the second item of one composition (`Comp 1_1.mov`). A default output
 /// name that another item of the queue already has is numbered the same way.
 #[test]