KCL: Revolve should create new solids (#7937)

When you extrude a sketch-on-face, you could either modify the original solid, or create a new one. These are known as extrude methods (Merge and New respectively).

Revolve, on the engine side, always does the equivalent of New for revolve, but the app wrongly thought it was doing a Merge.

This meant KCL got confused about whether a revolved SoF should be treated as its own object or part of something else's. Here's an easy way to visualize the problem:

Before:
<img width="1840" height="1037" alt="Screenshot 2025-07-30 at 2 07 42 PM" src="https://github.com/user-attachments/assets/f82f5107-1017-4b12-91f6-baf6ea3a6797" />

After:
<img width="1840" height="1151" alt="Screenshot 2025-07-30 at 2 07 10 PM" src="https://github.com/user-attachments/assets/1be72b33-a76b-47b0-9357-8583f86204fc" />

Fixes #6925

Author: adamchalmers

rust/kcl-lib/src/simulation_tests.rs

@@ -3838,3 +3838,24 @@ mod tag_inner_face {
         super::execute(TEST_NAME, true).await
     }
 }
+mod revolve_on_face {
+    const TEST_NAME: &str = "revolve_on_face";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}

rust/kcl-lib/src/std/extrude.rs

@@ -332,6 +332,9 @@ pub(crate) async fn do_post_extrude<'a>(
         // Ok so you would think that the id would be the id of the solid,
         // that we passed in to the function, but it's actually the id of the
         // sketch.
+        //
+        // Why? Because when you extrude a sketch, the engine lets the solid absorb the
+        // sketch's ID. So the solid should take over the sketch's ID.
         id: sketch.id,
         artifact_id: solid_id,
         value: new_value,

rust/kcl-lib/src/std/revolve.rs

@@ -127,14 +127,14 @@ async fn inner_revolve(
 
     let mut solids = Vec::new();
     for sketch in &sketches {
-        let id = exec_state.next_uuid();
+        let new_solid_id = exec_state.next_uuid();
         let tolerance = tolerance.as_ref().map(|t| t.to_mm()).unwrap_or(DEFAULT_TOLERANCE_MM);
 
         let direction = match &axis {
             Axis2dOrEdgeReference::Axis { direction, origin } => {
                 exec_state
                     .batch_modeling_cmd(
-                        ModelingCmdMeta::from_args_id(&args, id),
+                        ModelingCmdMeta::from_args_id(&args, new_solid_id),
                         ModelingCmd::from(mcmd::Revolve {
                             angle,
                             target: sketch.id.into(),
@@ -160,7 +160,7 @@ async fn inner_revolve(
                 let edge_id = edge.get_engine_id(exec_state, &args)?;
                 exec_state
                     .batch_modeling_cmd(
-                        ModelingCmdMeta::from_args_id(&args, id),
+                        ModelingCmdMeta::from_args_id(&args, new_solid_id),
                         ModelingCmd::from(mcmd::RevolveAboutEdge {
                             angle,
                             target: sketch.id.into(),
@@ -198,14 +198,14 @@ async fn inner_revolve(
         solids.push(
             do_post_extrude(
                 sketch,
-                id.into(),
+                new_solid_id.into(),
                 TyF64::new(0.0, NumericType::mm()),
                 false,
                 &super::extrude::NamedCapTags {
                     start: tag_start.as_ref(),
                     end: tag_end.as_ref(),
                 },
-                kittycad_modeling_cmds::shared::ExtrudeMethod::Merge,
+                kittycad_modeling_cmds::shared::ExtrudeMethod::New,
                 exec_state,
                 &args,
                 edge_id,