AI import: a compound path whose subpaths' group is marked like a look keeps its holes (fixes #980)

crates/eps/src/import/ai/read.rs

@@ -870,7 +870,9 @@ impl<'a> Reader<'a> {
         let mut painted = None;
         let node = match kind {
             // A compound path holding a group (its drawn look) is that look: its paths paint apart.
-            Kind::Compound if kids.iter().any(|k| self.looks.contains(&k.id)) => {
+            // Some files mark every group so, the plain one holding the subpaths too (#980): one
+            // paint for all its paths keeps it one compound path, its holes cut.
+            Kind::Compound if kids.iter().any(|k| self.looks.contains(&k.id) && paints_apart(k)) => {
                 let (children, clip) = self.clip_first(kids, &clips);
                 self.new_node(NodeKind::Group { children, clip }, &gs)
             }
@@ -2203,6 +2205,19 @@ fn ungrouped(kids: Vec<Node>) -> Vec<Node> {
     out
 }
 
+/// Whether `look`'s paths don't all paint the same.
+fn paints_apart(look: &Node) -> bool {
+    fn leaves<'a>(n: &'a Node, out: &mut Vec<&'a Node>) {
+        match &n.kind {
+            NodeKind::Group { children, .. } => children.iter().for_each(|c| leaves(c, out)),
+            _ => out.push(n),
+        }
+    }
+    let mut paths = vec![];
+    leaves(look, &mut paths);
+    paths.windows(2).any(|w| matches!(w, [a, b] if a.appearance != b.appearance))
+}
+
 fn path_rule(n: &Node) -> FillRule {
     match &n.kind {
         NodeKind::Path { rule, .. } | NodeKind::Compound { rule, .. } => *rule,

crates/eps/src/import/ai/tests.rs

@@ -446,6 +446,21 @@ fn a_compound_path_holding_its_drawn_look_paints_its_paths_apart() {
     assert_eq!(fills, [Some(Color::rgb(1.0, 0.0, 0.0)), Some(Color::rgb(0.0, 0.0, 1.0))], "{a:#?}");
 }
 
+#[test]
+fn a_compound_path_of_a_plain_group_stays_one_compound_path() {
+    // GUARDS: #980. Files write `9 () XW` after every group, the one a compound path keeps its
+    // subpaths in too: read as a drawn look, the compound became a group of filled paths, its
+    // holes filled in. Here a ring (outer path, inner one reversed, one paint) and a path beside it.
+    let ring = format!("{RED}1 D\n{}f\n0 D\n{}f\n", rect_path(0.0, 0.0, 20.0, 20.0), "5 5 m\n15 5 L\n15 15 L\n5 15 L\n5 5 L\n");
+    let art_ = format!("0 Ae\nu\n0 Ae\n*u\n0 Ae\nu\n{ring}U\n9 () XW\n*U\n{}f\nU\n9 () XW\n", rect_path(8.0, 8.0, 12.0, 12.0));
+    let a = art(&read_ok(&layer(&art_)).doc);
+    let NodeKind::Group { children, .. } = &a[0].kind else { panic!("{a:#?}") };
+    let NodeKind::Compound { children: subpaths, .. } = &children[0].kind else { panic!("a compound path: {:#?}", children[0]) };
+    assert_eq!(subpaths.len(), 2, "{subpaths:#?}");
+    assert!(subpaths.iter().all(|p| matches!(p.kind, NodeKind::Path { .. })));
+    assert_eq!(fill(&children[0]).color(), Some(Color::rgb(1.0, 0.0, 0.0)));
+}
+
 #[test]
 fn gradients_through_a_skewed_matrix() {
     // GUARDS: a sheared `Xm` leaves the matrix's columns oblique. A linear ramp runs along the