From b23d64bec02edf70b7dc1414b708e04b1c23582c Mon Sep 17 00:00:00 2001
From: Stephen Chung <schungx@live.com>
Date: Thu, 5 May 2022 21:34:15 +0800
Subject: [PATCH] Fix bug with using self-contained AST with call_fn.

---
 CHANGELOG.md       |  9 +++++++++
 src/api/call_fn.rs | 11 +++++++++++
 tests/modules.rs   | 10 +++++++---
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1cf25db..8f5a5706 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,15 @@
 Rhai Release Notes
 ==================
 
+Version 1.8.0
+=============
+
+Bug fixes
+---------
+
+* Self-contained `AST` now works properly with `Engine::call_fn`.
+
+
 Version 1.7.0
 =============
 
diff --git a/src/api/call_fn.rs b/src/api/call_fn.rs
index 41d1e414..d6290163 100644
--- a/src/api/call_fn.rs
+++ b/src/api/call_fn.rs
@@ -244,6 +244,12 @@ impl Engine {
 
         let orig_scope_len = scope.len();
 
+        #[cfg(not(feature = "no_module"))]
+        let orig_embedded_module_resolver = std::mem::replace(
+            &mut global.embedded_module_resolver,
+            ast.resolver().cloned(),
+        );
+
         if eval_ast && !statements.is_empty() {
             self.eval_global_statements(scope, global, caches, statements, &[ast.as_ref()], 0)?;
 
@@ -278,6 +284,11 @@ impl Engine {
             0,
         )?;
 
+        #[cfg(not(feature = "no_module"))]
+        {
+            global.embedded_module_resolver = orig_embedded_module_resolver;
+        }
+
         #[cfg(feature = "debugging")]
         if self.debugger.is_some() {
             global.debugger.status = crate::eval::DebuggerStatus::Terminate;
diff --git a/tests/modules.rs b/tests/modules.rs
index 4394d893..69e2ef82 100644
--- a/tests/modules.rs
+++ b/tests/modules.rs
@@ -263,11 +263,11 @@ fn test_module_resolver() -> Result<(), Box<EvalAltResult>> {
     #[cfg(not(feature = "no_function"))]
     {
         let script = r#"
-            fn foo() {
+            fn foo(x) {
                 import "hello" as h;
-                h::answer
+                h::answer * x
             }
-            foo() + { import "hello" as h; h::answer }
+            foo(1) + { import "hello" as h; h::answer }
         "#;
         let mut scope = Scope::new();
 
@@ -278,6 +278,10 @@ fn test_module_resolver() -> Result<(), Box<EvalAltResult>> {
         assert_eq!(engine.eval_ast::<INT>(&ast)?, 84);
 
         assert!(engine.eval::<INT>(script).is_err());
+
+        let result: INT = engine.call_fn(&mut Scope::new(), &ast, "foo", (2 as INT,))?;
+
+        assert_eq!(result, 84);
     }
 
     Ok(())