From b630b8a2a69eb82194214a8117191bc7005038e7 Mon Sep 17 00:00:00 2001
From: Catrope <roan.kattouw@gmail.com>
Date: Wed, 3 Oct 2012 17:51:10 -0700
Subject: [PATCH] Support custom hashes in ve.getHash()

Change-Id: I9193472773b999b45ce850a609ad5fe141421dbf
---
 modules/ve/ve.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/modules/ve/ve.js b/modules/ve/ve.js
index 4fd424b5d3..5b0a489e83 100644
--- a/modules/ve/ve.js
+++ b/modules/ve/ve.js
@@ -241,6 +241,10 @@
 	 * argument of JSON.stringify and sort the object by key as it's being serialized. This may or may
 	 * not be the fastest way to do this; we should investigate this further.
 	 *
+	 * Objects an arrays are hashed recursively. When hashing an object that has a .getHash()
+	 * function, we call that function and use its return value rather than hashing the object
+	 * ourselves. This allows classes to define custom hashing.
+	 *
 	 * @static
 	 * @method
 	 * @param {Object} val Object to generate hash for
@@ -263,9 +267,13 @@
 	 */
 	ve.getHash.keySortReplacer = function ( key, val ) {
 		var normalized, keys, i, len;
-		// Only normalize objects when the key-order is ambiguous
-		// (e.g. any object not an array).
+		if ( val && typeof val.getHash === 'function' ) {
+			// This object has its own custom hash function, use it
+			return val.getHash();
+		}
 		if ( !ve.isArray( val ) && Object( val ) === val ) {
+			// Only normalize objects when the key-order is ambiguous
+			// (e.g. any object not an array).
 			normalized = {};
 			keys = ve.getObjectKeys( val ).sort();
 			i = 0;