From e2dcf47c56ea34fdafae6c07d03bcc309128cda5 Mon Sep 17 00:00:00 2001
From: David Wendt <dcrkid@yahoo.com>
Date: Tue, 22 Oct 2019 15:18:40 -0400
Subject: [PATCH] Add a method to force resolve a `ReturnValue` on the Rust
 stack via recursion.

---
 core/src/avm1.rs              | 37 ++++++++++++++++++++++-------------
 core/src/avm1/return_value.rs | 20 +++++++++++++++++++
 2 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/core/src/avm1.rs b/core/src/avm1.rs
index 98ea731fb..e68df73c5 100644
--- a/core/src/avm1.rs
+++ b/core/src/avm1.rs
@@ -301,23 +301,32 @@ impl<'gc> Avm1<'gc> {
     pub fn run_current_frame(
         &mut self,
         context: &mut UpdateContext<'_, 'gc, '_>,
+        stop_frame: GcCell<'gc, Activation<'gc>>,
     ) -> Result<(), Error> {
-        let stop_frame = *self.stack_frames.last().unwrap();
-        let stop_frame_id = self.stack_frames.len() - 1;
-
-        while self
-            .stack_frames
-            .get(stop_frame_id)
-            .map(|fr| GcCell::ptr_eq(stop_frame, *fr))
-            .unwrap_or(false)
-        {
-            self.with_current_reader_mut(context, |this, r, context| {
-                this.do_next_action(context, r)
-            })
-            .unwrap()?;
+        let mut stop_frame_id = None;
+        for (index, frame) in self.stack_frames.iter().enumerate() {
+            if GcCell::ptr_eq(stop_frame, *frame) {
+                stop_frame_id = Some(index);
+            }
         }
 
-        Ok(())
+        if let Some(stop_frame_id) = stop_frame_id {
+            while self
+                .stack_frames
+                .get(stop_frame_id)
+                .map(|fr| GcCell::ptr_eq(stop_frame, *fr))
+                .unwrap_or(false)
+            {
+                self.with_current_reader_mut(context, |this, r, context| {
+                    this.do_next_action(context, r)
+                })
+                .unwrap()?;
+            }
+
+            Ok(())
+        } else {
+            Err("Attempted to run a frame not on the current interpreter stack".into())
+        }
     }
 
     /// Run a single action from a given action reader.
diff --git a/core/src/avm1/return_value.rs b/core/src/avm1/return_value.rs
index 717b9eefb..47f45fcd4 100644
--- a/core/src/avm1/return_value.rs
+++ b/core/src/avm1/return_value.rs
@@ -109,6 +109,26 @@ impl<'gc> ReturnValue<'gc> {
         };
     }
 
+    /// Force a return value to resolve on the Rust stack by recursing back
+    /// into the AVM.
+    pub fn resolve(
+        self,
+        avm: &mut Avm1<'gc>,
+        context: &mut UpdateContext<'_, 'gc, '_>,
+    ) -> Result<Value<'gc>, Error> {
+        use ReturnValue::*;
+
+        match self {
+            Immediate(val) => Ok(val),
+            ResultOf(frame) => {
+                avm.run_current_frame(context, frame)?;
+
+                avm.pop()
+            }
+            NoResult => Err("Attempted to resolve a no-result return value".into()),
+        }
+    }
+
     /// Consumes the given return value.
     ///
     /// This exists primarily so that users of return values can indicate that