From dff124b2428e136ca29026225aaacefc9e4448b2 Mon Sep 17 00:00:00 2001
From: Stephen Chung <schungx@live.com>
Date: Sat, 6 Feb 2021 22:16:05 +0800
Subject: [PATCH] Save functions resolution cache during script call.

---
 src/fn_call.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/fn_call.rs b/src/fn_call.rs
index 03d9e33a..e309a8db 100644
--- a/src/fn_call.rs
+++ b/src/fn_call.rs
@@ -392,10 +392,10 @@ impl Engine {
 
         // Merge in encapsulated environment, if any
         let mut lib_merged: StaticVec<_>;
+        let mut old_cache = None;
 
         let unified_lib = if let Some(ref env_lib) = fn_def.lib {
-            // If the library is modified, clear the functions lookup cache
-            state.functions_cache.clear();
+            old_cache = Some(mem::take(&mut state.functions_cache));
 
             lib_merged = Default::default();
             lib_merged.push(env_lib.as_ref());
@@ -467,6 +467,10 @@ impl Engine {
         mods.truncate(prev_mods_len);
         state.scope_level = orig_scope_level;
 
+        if let Some(cache) = old_cache {
+            state.functions_cache = cache;
+        }
+
         result
     }