Pathfinder panel: a group selected alone counts its nested shapes, so an expanded stroke keeps the Shape Modes enabled (fixes #1635)

crates/engine/src/cmd/mod.rs

@@ -493,6 +493,9 @@ pub use flatten::FlattenOptions;
 /// A built-in or saved flattener preset ([`crate::Prefs::flattener_presets`]).
 pub use flatten::FlattenerPreset;
 
+/// The shapes a group selected alone gives the Pathfinder panel.
+pub use pathops::shape_count;
+
 /// Command ids kept only so older scripts keep working: `(alias, the command it duplicates)`.
 /// They run as before but the command palette leaves them out (it lists the command once).
 pub const ALIASES: &[(&str, &str)] = &[("object.convertDocumentColorMode", "file.documentColorMode")];

crates/engine/src/cmd/pathops.rs

@@ -258,6 +258,14 @@ fn leaves(n: &Node, out: &mut Vec<Node>) {
     }
 }
 
+/// How many shapes a Pathfinder operation takes from `n` selected alone: its leaf shapes, however
+/// deep its groups nest (an expanded stroke is a group inside the group, #1635).
+pub fn shape_count(n: &Node) -> usize {
+    let mut lv = vec![];
+    leaves(n, &mut lv);
+    lv.len()
+}
+
 /// A node for `path`: a plain path for one subpath, else a compound path.
 pub(crate) fn shape_node(d: &mut Document, path: PathData, style_src: Option<&Node>) -> Node {
     let id = d.alloc_id();