From c903f0e3285b3e0d6bf26f5e7c80a5b4116f5458 Mon Sep 17 00:00:00 2001
From: "igor%mir2.org" <igor%mir2.org@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Wed, 14 May 2003 14:51:00 +0000
Subject: [PATCH] In getByGetter/setBySetter with slot.delegateTo avoid
 potentially expensive checks for start type if this == start.

git-svn-id: svn://10.0.0.236/trunk@142438 18797224-902f-48f8-a5cc-f745e15eee43
---
 .../mozilla/javascript/ScriptableObject.java  | 51 ++++++++++++-------
 1 file changed, 32 insertions(+), 19 deletions(-)

diff --git a/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java b/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java
index e1f8dc00c20..21525f854b6 100644
--- a/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java
+++ b/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java
@@ -179,30 +179,38 @@ public abstract class ScriptableObject implements Scriptable, Serializable,
     }
 
     private Object getByGetter(GetterSlot slot, Scriptable start) {
-        try {
-            if (slot.delegateTo == null) {
+        Object getterThis;
+        Object[] args;
+        if (slot.delegateTo == null) {
+            if (start != this) {
                 // Walk the prototype chain to find an appropriate
                 // object to invoke the getter on.
                 Class clazz = slot.getter.getDeclaringClass();
                 while (!clazz.isInstance(start)) {
                     start = start.getPrototype();
+                    if (start == this) {
+                        break;
+                    }
                     if (start == null) {
                         start = this;
                         break;
                     }
                 }
-                return slot.getter.invoke(start, ScriptRuntime.emptyArgs);
             }
-            Object[] args = { this };
-            return slot.getter.invoke(slot.delegateTo, args);
-        }
-        catch (InvocationTargetException e) {
-            throw WrappedException.wrapException(e);
-        }
-        catch (IllegalAccessException e) {
-            throw WrappedException.wrapException(e);
+            getterThis = start;
+            args = ScriptRuntime.emptyArgs;
+        } else {
+            getterThis = slot.delegateTo;
+            args = new Object[] { this };
         }
 
+        try {
+            return slot.getter.invoke(getterThis, args);
+        } catch (InvocationTargetException e) {
+            throw WrappedException.wrapException(e);
+        } catch (IllegalAccessException e) {
+            throw WrappedException.wrapException(e);
+        }
     }
 
     /**
@@ -273,14 +281,19 @@ public abstract class ScriptableObject implements Scriptable, Serializable,
         Object actualArg
                 = FunctionObject.convertArg(cx, start, value, desired);
         if (slot.delegateTo == null) {
-            // Walk the prototype chain to find an appropriate
-            // object to invoke the setter on.
-            Class clazz = slot.setter.getDeclaringClass();
-            while (!clazz.isInstance(start)) {
-                start = start.getPrototype();
-                if (start == null) {
-                    start = this;
-                    break;
+            if (start != this) {
+                // Walk the prototype chain to find an appropriate
+                // object to invoke the setter on.
+                Class clazz = slot.setter.getDeclaringClass();
+                while (!clazz.isInstance(start)) {
+                    start = start.getPrototype();
+                    if (start == this) {
+                        break;
+                    }
+                    if (start == null) {
+                        start = this;
+                        break;
+                    }
                 }
             }
             setterThis = start;