From 06df03f78cb1b23f4e9bd10d7f7f4fab3a16e86f Mon Sep 17 00:00:00 2001
From: Steve Bennett <steveb@workware.net.au>
Date: Sat, 16 Sep 2017 13:29:34 +1000
Subject: defer: fast lookup existence of $jim::defer

This speeds up call frame destruction in the common
case that $jim::defer does not exist.

Signed-off-by: Steve Bennett <steveb@workware.net.au>
---
 jim.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/jim.c b/jim.c
index 131924c..4489f50 100644
--- a/jim.c
+++ b/jim.c
@@ -5034,10 +5034,17 @@ static int JimDeleteLocalProcs(Jim_Interp *interp, Jim_Stack *localCommands)
  */
 static int JimInvokeDefer(Jim_Interp *interp, int retcode)
 {
-    Jim_Obj *objPtr = Jim_GetVariableStr(interp, "jim::defer", JIM_NONE);
-    int ret = JIM_OK;
+    Jim_Obj *objPtr;
+
+    /* Fast check for the likely case that the variable doesn't exist */
+    if (Jim_FindHashEntry(&interp->framePtr->vars, "jim::defer") == NULL) {
+        return retcode;
+    }
+
+    objPtr = Jim_GetVariableStr(interp, "jim::defer", JIM_NONE);
 
     if (objPtr) {
+        int ret = JIM_OK;
         int i;
         int listLen = Jim_ListLength(interp, objPtr);
         Jim_Obj *resultObjPtr;
-- 
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