.ai save: the editing copy draws the artboards' background colors

The PDF pages of a .ai draw each artboard's background color (Include
Artboard Fill, on by default), but the editing copy of the art left it
out, so the two differed and the file reopened from its PDF part. The
editing copy now takes the same option.

crates/engine/src/cmd/fileio/save.rs

@@ -648,11 +648,13 @@ pub(super) fn encode_ai(cmd: &str, f: &Format, doc: &Document, p: &Value) -> Res
             resolved = d;
             (&resolved, w)
         };
+        // With the artboards' background colors, as the pages draw them.
+        let art = super::export::with_artboard_fills(art, &params, 0..art.artboards.len()).map_err(|e| bad(cmd, e))?;
         let o = vectorcraft_eps::AiEditingOptions {
             title: doc.title.clone(),
             created: doc.metadata.created.or_else(vectorcraft_doc::metadata::output_time),
         };
-        let (data, lost) = vectorcraft_eps::ai_private_data(art, &o).map_err(|e| bad(cmd, e))?;
+        let (data, lost) = vectorcraft_eps::ai_private_data(&art, &o).map_err(|e| bad(cmd, e))?;
         // Placed files that weren't found are written as their previews here too.
         resolved_warnings.extend(lost);
         carries_editing.set(true);

crates/engine/src/cmd/fileio/tests_artboard_fill.rs

@@ -97,6 +97,18 @@ fn pdf_and_svg_show_the_color_and_their_editing_data_keeps_it_as_the_artboards()
     assert_eq!(back.layers.len(), doc.layers.len(), "no art made of it");
 }
 
+#[test]
+fn the_ai_editing_copy_for_other_apps_draws_the_color_as_the_pages_do() {
+    let mut s = session();
+    let opts = LoadOptions { native: false, ..Default::default() };
+    for (more, fill) in [(json!({}), true), (json!({"includeArtboardFill": false}), false)] {
+        let l = load::load_with("a.ai", &file(&mut s, with(json!({"format": "ai"}), &more)), &opts).unwrap();
+        assert!(l.editing_data && !l.restored, "{more}: {:?}", l.warnings);
+        let names: Vec<String> = l.doc.layers.iter().filter_map(|l| l.name.clone()).collect();
+        assert_eq!(names.iter().any(|n| n == "Artboard Fill"), fill, "{more}: {names:?}");
+    }
+}
+
 #[test]
 fn eps_and_postscript_print_draw_the_color() {
     let mut s = session();