A panic while healing a boolean result no longer ends the boolean: a shallow, wide loft cut from a top face (556.68 x 99 down 4 mm to 80 x 80 in a 900 x 480 x 160 slab) failed with "called Option::unwrap() on a None value"

heal_keep evaluated the result's intersection curves outside any guard. truck panics where such a curve no longer evaluates, and the panic escaped boolean_whole, so the retries and fallbacks that would have succeeded never ran. heal_keep now runs under guard and returns the solid unhealed when healing panics (as its doc already promised for failures), and the boolean builds its result body under guard too, so a result that cannot be built counts as a failed attempt.

Tests: shallow_loft_cut_from_the_top_face replays examples/regressions/shallow_loft_cut_from_top_face.json and checks the exact prismatoid volume (fails on main with the panic).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/kernel/src/heal.rs

@@ -404,6 +404,12 @@ pub fn heal(solid: Solid, size: f64) -> Solid {
 
 /// [`heal`], keeping faces apart along lines they were split along on purpose.
 pub(crate) fn heal_keep(solid: Solid, size: f64, keep: &[Vec<Vec3>]) -> Solid {
+    // Edges a boolean made are intersection curves, which panic where they no longer
+    // evaluate; the solid then stays as it is.
+    crate::guard("heal", || Ok(heal_shells(&solid, size, keep))).ok().flatten().unwrap_or(solid)
+}
+
+fn heal_shells(solid: &Solid, size: f64, keep: &[Vec<Vec3>]) -> Option<Solid> {
     let tol = (size * 1e-7).max(1e-9);
     let mut shells = Vec::new();
     let mut changed = false;
@@ -428,9 +434,9 @@ pub(crate) fn heal_keep(solid: Solid, size: f64, keep: &[Vec<Vec3>]) -> Solid {
         shells.push(cur);
     }
     if !changed {
-        return solid;
+        return None;
     }
-    Solid::try_new(shells).unwrap_or(solid)
+    Solid::try_new(shells).ok()
 }
 
 #[cfg(test)]

crates/kernel/src/ops.rs

@@ -296,7 +296,7 @@ fn boolean_whole(a: &Body, b: &Body, op: BoolOp) -> Result<Option<Body>> {
                     empty_votes += 1;
                     last = "empty result".into();
                 }
-                Ok(s) => match Body::new(crate::heal::heal_keep(s, size, &keep)) {
+                Ok(s) => match guard("boolean result", || Body::new(crate::heal::heal_keep(s, size, &keep))) {
                     Ok(body) => {
                         let (ok, v) = check(&body);
                         if ok {